An escaped convict, who is said to prey on elderly and vulnerable people, is being hunted by Hillingdon Police.

Allen Johnson, 63, escaped from Leyhill Prison in March 2000, and has since been linked to a string of offences across London.

In one incident, Johnson allegedly conned a pensioner from Uxbridge out of 500. He is said to have befriended the 78-year-old who was partially sighted, escorting him to his warden controlled home in Uxbridge.

Police say he persuaded the pensioner he could get him a mattress and a chair for a very good price, and escorted him to his building society where the elderly man withdrew 500 in cash. He never saw Johnson again.

DS Shaun Dodds, from Ruislip police station, said: "Police have been actively seeking Johnson since then and he is still unlawfully at large. He must be brought to justice. He is a predatory individual, specifically targeting the elderly and vulnerable to fund his criminal lifestyle."

He added: "Any person who has any information as to his whereabouts is urged to contact the police."

A police spokesman said: "Johnson's normal method is to befriend victims in the street or public places using a variety of stories to gain their confidence before stealing property from their homes or stealing cheques. He also obtains money in advance of services he never provides.

"He is known to travel extensively throughout the south east. He uses guest houses and hostel accommodation for short periods at a time and has claimed before to have connections with local authorities and charities such as Age Concern."

Johnson is known to use aliases including: Alan Johnson, Alan Jackson, Sam Cutler, Peter Burridge, Brian Saunders, Allen Williams, Sam Wilson, Steven Johnson, Alan Hinkley, David Cox, Brian Mayhew, Peter Manley, Peter Mannard, Colin Mayhew, John Townsend, Brian Willis, and Peter Gold.

He is described as white, 5ft 7ins tall, with hazel eyes and grey receding hair. He has numerous tattoos on his arms including one saying 'Mum' and 'Rita'.

Anyone with information is urged to contact police on 020 8649 1346