A SURVEILLANCE drone worth £30,000 that was being used by Sellafield during an industrial protest crashed to the ground - after being attacked by an angry seagull.

Bosses were using the drone to monitor traffic flow into the site as union members picketed the site’s main gate as part of the ongoing strike by members of Unite over what the union says is unacceptably low pay for Mitie staff who provide catering, cleaning, security, and laundry services on June 13.

An insider from the plant said: “It came down after being attacked by seagull.

“Thankfully, it didn’t fall on anybody.”

Wildlife experts said the bird responsible is most likely to have been an adult herring gull defending its nest or its chicks.

Unite’s regional official Ryan Armstrong said he had noticed the drone’s absence in recent days.

“A police officer told me he thought it might be because it was too windy,” he said.

A Sellafield spokesman said the drone was being used to monitor traffic as union members were picketing duties near the gates.

The protest usually involves activists speaking to staff as they arrive for work by car.

“We use unmanned aerial vehicles (UAVs) for a number of tasks at Sellafield, in common with many industrial sites around the world,” said the spokesman.

“This is done by trained operators in a strictly-controlled environment and with reference to all relevant regulation and industry best practice.

“We’ve been using a UAV to support Cumbria Police in the safe management of the recent industrial action.

“This is to monitor traffic flow to inform police decision making on roads management.

“These operations were subject to a rigorous risk assessment and involved the UAV flying to a fixed height vertically in a safe area before being returned to ground.

“Unfortunately the UAV used for the task failed and crash landed during operations on 13 June.

“No one was injured and there was no risk to nuclear safety. We have referred the incident to the Air Accidents Investigation Branch.”

Mitie’s 180 Unite members have been taking part in the industrial action since April.

Earlier this month, they said a survey of members had revealed many faced work stress, caused by low pay, too much work, and bullying.

Herring gulls are currently on the international “red list” of endangered species, with the birds having seen a marked decline in their breeding ranges over the last 25 years.

Nobody from Mitie was available for comment.