A youth worker has been jailed for almost eight years after committing "wretched" and "wicked" child sex crimes.

Carlisle Crown Court heard that Leigh Mavir, 29, groomed his teenage victim before exploiting her over an 11-month period.

He was sentenced having pleaded guilty to 12 offences.

Mavir admitted six counts of sexual activity with a child; three charges of taking indecent images of his young victim; and three of making indecent photographs of other, unknown children having downloaded almost 1,000 pictures.

Prosecutor Antony Longworth outlined the grim details of the offences.

"The defendant was working as a youth worker," said Mr Longworth. "The defendant himself had a sexual interest in children."

When police began to investigate his illegal activity, Mavir denied any wrongdoing.

But when belongings were seized from him, officers found he had amassed a sick library featuring hundreds of illegal images of children.

Almost 100 of these had been taken of the victim and were classed in category A - the most serious.

The court heard the crimes had a "profound and significant" impact on the girl.

Barrister Greg Hoare addressed Judge Peter Davies on Mavir's behalf.

"He knows his greatest mitigation - the only mitigation - is the fact he pleaded guilty," said Mr Hoare.

"He appreciates there is a problem and intends to avail himself of all the help he can get to ensure he can benefit from that and doesn't commit any further offences in the future, either on the internet or in dealings with any children who are under-age."

Mr Hoare added: "He will find prison a very difficult environment to cope with, in particular for this type of offending."

Mavir was jailed for 90 months by Judge Davies, who said: "Seven-and-a-half years for these wretched, corrupting, wicked offences that you committed on this young girl."

In addition Mavir, of The Crescent, Egremont, was made subject to the sex offender notification requirements and the strict terms of a sexual harm prevention order. These will each be in force for an indefinite period.

Mavir was also told he will be subject to the safeguarding provisions which protect children and vulnerable adults.