HEAVY police presence in York today is due to a prisoner escaping custody, it is understood.

North Yorkshire Police will not confirm what the increased presence in the Clifton area is in relation to, only stating it was part of an ongoing investigation.

A number of sources have told our sister paper, the York Press, a man was arrested by armed police in the Clifton area last night.

He is understood to have been taken into custody, then transported to York Hospital.

The Press understands the man then managed to escaped police officers after leaving hospital, and has been on the run ever since.

The police helicopter, run by the National Police Air Service, was called out in the early hours of today, and the helicopter remained over the city this afternoon as searches continue.

North Yorkshire Police said they would not add to their initial statement.