Queen's safety momentarily threatened

Authorities raised a high-level security concern after they found an armed man roaming the grounds of Windsor Castle on Christmas Day.

The man, who was identified to be a 19-year-old individual from Southampton appeared to be carrying a crossbow.

Officers scrambled to the scene and arrested the trespasser.

At the time the Queen was at her personal quarters where she was waiting for her son Prince Charles and Prince Edward.

"Security controllers monitoring the CCTV couldn’t believe their eyes when they spotted the man carrying what appeared to be a crossbow and scrambled armed police to the scene immediately as a top-level emergency," sources said.

"A full-scale protection plan was executed to ensure the safety of the Queen, who was in her personal quarters.

"It was a really professional response from everyone, but it was hugely alarming to witness the intruder on the scene.

"There were real concerns the situation could have massively escalated having such a dangerous weapon to deal with.

"When word got out that he had been apprehended, everyone breathed a huge sigh of relief – but it’s obviously tremendously concerning."