Nigel Clibbens is still unable to name the mystery "billionaire" who stalked Carlisle United for 650 days. He is still unable to say even when the club will be allowed to name him.

What he is allowed to talk about - what is not governed by non-disclosure agreements and legal threats - is the general pattern of a controversial period in the Blues' recent history, which finally ended in late February.

United are trying to move on from the "potential overseas investor" saga, having entered a new financial arrangement with the Edinburgh Woollen Mill. Yet the subject of their previous suitor, with his long periods of silence and apparently unsatisfactory offer, remains a big grey area.

It is the Carlisle hierarchy's first interview on the subject with the News & Star all season and we start with the traditional dance around identifying the individual. One name - Canada-based Syrian Yahya Kirdi - has done the rounds yet chief executive Clibbens refused to confirm or deny his involvement when asked by BBC Radio Cumbria recently.

Why could he not even be ruled out? "Until we get the legal position confirmed, it would be wrong of me to get into anything at all about who it is or who it isn't," Clibbens says. "I don't want to do anything that can inadvertently put the club into a risk position."

Clibbens accepts that this reply will not temper speculation, while this also leads to a broader debate on how United handled the saga, from an announcement of "genuine and firm" interest on May 19, 2015 to the increasingly sceptical response as it went on.

It also lets us examine the end game, when the Carlisle United Official Supporters' Club were finally invited into the fold, signing a confidentiality agreement before meeting the investor last October, then joining the owners in signing another as an offer was made four months later. Until then, co-owners Andrew Jenkins and John Nixon had been operating under unwritten confidentiality, or "professional trust" as Clibbens puts it.

In light of criticism they have also faced since it all ended, did CUOSC ask for time to study that October agreement's legal implications? "They can answer for themselves, but I was at the meeting and think, having finally got this person there, and being able to meet him, the view was taken that that was going to be of far more benefit than seeking to defer," Clibbens says.

"They could have asked the question, but my strong view was they wouldn't have been allowed in the room…and they might not have seen him again."

What would such a response would have said about this suitor? Clibbens says United's other owners chose to "note" the investor's stance and allowed it to inform their overall view, even as they continued talks.

"With hindsight, you could have played hard-ball and forced his hand earlier," Clibbens says. "But, in the end, we got an offer to consider. That's what it was all about. It's about how you get to the end game. But you cannot and do not forget the journey to get there."

Clibbens says this mindset also applied to the extremely long time already elapsed. "The assessment I made was that if the offer, the plan, the vision was strong enough, that could outweigh all the other points you make. But it needed to be strong enough to be judged in that context. The longer it grew, the stronger the proposal had to be to stand up to the scrutiny."

Plainly it was not so strong, yet Clibbens is adamant all the waiting did not damage the club materially. "It didn't stop other people coming in," he says, adding that tentative phonecalls from other people interested in investing were received amid the saga, not that they led to anything.

CUOSC recently said the overseas investor's eventual offer would have invited "ridicule" had it been put to fans. Clibbens will not "simply endorse" that term, but does admit the long wait for a face-to-face meeting with the investor undermined confidence among fans and "trust and credibility" in the eyes of directors. He says the mystery man presented some "good plans" for United's ground, but his budget forecast for reaching the Championship was unrealistically low.

Was there no point when these plans could have been shown to the wider fanbase? "We all agreed it was imperative that he, in person, first met the CUOSC board, and then was able to go to a public meeting of fans to explain those plans. That was always in our mind where we got to the point where a deal was done.

"But we didn't get there, because other aspects of the deal, not just his plans, didn't stand up to the scrutiny of the spotlight we put them under."

The spotlight had also fallen, from fans, on the way United both launched and handled the saga, particularly by using the word "billionaire" - originally in a tweet from former vice-president Andy Bell, later endorsed by Nixon.

The latter, Clibbens admits, proved particularly costly, setting the stage for expectations the club found almost impossible to manage. A lesson learned, he insists.

What, though, of the "research" Nixon cited that led him to claim that our man was "indeed" a billionaire? Firstly Clibbens, who was not at the club at this point, says this was an overall directors' view, not merely Nixon's.

Secondly, the chief executive says the credibility of the offer that materialised was more important than the person's individual wealth. Pushed on the "research", Clibbens says he has not asked his boardroom colleagues about the specifics, but suggests enquiries to the investor's agent and some other contacts in the game may have led to that conclusion, along with other deals he had "tried to do".

Tried? A billionaire? "People who do deals don't always act for themselves," Clibbens says. "They can be frontmen for other people."

A straight question of whether he was indeed a billionaire does not elicit a straight yes or no. Clibbens, though, feels confident of the man's credentials and says United's enquiries with the football authorities brought no advice that they should curtail talks.

So the Blues, had they pushed it through, would not have been another Morecambe? "No, I don't think we'd have had that situation. We thought he'd have been good for the money to do the deal he wanted to do."

A lingering accusation is that the "billionaire" episode was launched in order to soften the blow of dropping the widely popular Andrew Lapping proposals in 2015. Clibbens refutes that this was the strategy. "The evidence I've seen is that the previous deal was facing trouble before this even emerged."

Was it not, though, an attempt to turn some of the heat down? "I don't think it was. I could understand that claim if the evidence shows it actually did turn the heat down. But in what they said about the reasons for the deal failing and about the new interest…it just turned the gas up."

On the billionaire approach, which United were notably "pleased" to announce, he adds: "At the time, from what I've been told, it was simply a case of positive news. I don't think it was more sophisticated than that. That's just my view.

"I think the directors tried to be truthful and honest about both deals. Whether the perception has turned out that way is for others to judge."

Clibbens is, of course, dealing with aspects of a story he was not around to handle until last summer. Another such moment was when Nixon refused to take questions on the matter in a radio interview in 2015.

This is now put down to "advice" from a PR person the club had engaged at the time. Clibbens does not comment further.

The chief executive does, though, admit that a sought-after meeting "never happened" in the infamous "five to 10 day" period when initial talks were supposed to advance. Indeed, it did not occur for well over a year.

"When we asked the reasons why, it was explained that he [the investor] was exploring other football clubs outside the UK, other business opportunities, and because the club was suffering from a flood [from December 2015] he wanted to see us get to a stable position.

"There's no getting away from the fact that a meeting didn't take place [in that period]. But it wasn't for the want of trying."

To many fans this period looked fishy, certainly where the investor's commitment was concerned. Why didn't United simply end it then? Clibbens says persisting with it did not cost the club anything and the owners were willing to risk hostility from some fans in order to exhaust its possibilities.

"As time has progressed, the cost in terms of reputational impact has been an increasing one," he says. "But singling out individuals is unfair. It has cast a shadow, as I have said on a number of occasions.

"The directors knew that, reputationally, they were going to take criticism. But they formed a judgement that, in the end, if they could get a deal for the greater good of the club, it would be worth it. They chose to put the interests of the club in front of themselves."

Was it all worth it, though - stretching out a situation with an unsuitable suitor that, to some, made the club's hierarchy a laughing stock?

"I think in the eyes of some people, it has been damaging," Clibbens says. "How do you repair that? What we have to have is a strong sense of direction as to what we're trying to do. We also need to be more forthright in what we say, and face up to some of these issues.

"There's no getting away from the fact that there are things the club do that will not be liked by some people. But we've got to try and get people to understand they are done with the best intentions of the club."

*Tomorrow: Clibbens on United's finances and the need for "succession" at the top