Gardaí are searching for a violent prisoner who escaped when prison staff bringing him from a hospital appointment stopped to buy him chips.

Lee McDonnell had been brought to the Mater hospital in Dublin’s north inner city from Portlaoise Prison on Wednesday morning. He escaped during the return journey.

He was in a prison van with three prison officers and when the staff stopped at the chip shop on Tyrconnell Road, Inchicore, to buy food for themselves and McDonnell.

When the officers opened the back door of the vehicle to give the 23-year-old Dubliner the food, he had slipped out of his handcuffs and burst past them, running from the scene.

A spokesman for the Irish Prison Service confirmed McDonnell had escaped, adding the Garda had immediately been informed.

He said the Irish Prison Service had launched its own investigation into how the escape had occurred.

McDonnell, of Lough Conn Road, Ballyfermot, west Dublin, has a total of 110 convictions. He was jailed in 2012. Subsequent convictions for crimes committed before he was jailed mean he was not due for release until 2019.

Two of the attacks he was serving sentences for occurred within a three hour period on January 21st, 2012.

He beat a shopkeeper with the butt of a replica gun during a robbery at Sarsfield Service Station, Ballyfermot, and was jailed for six years, with three suspended, in November 2012.

In February of this year he was back before the courts and was jailed for nine years with two suspended for a violent attack on a man in his home on the same day as the petrol station attack.

Dublin Circuit Criminal Court was told McDonnell and an accomplice “savagely” attacked a home owner to get keys for a car they used in service station robbery three hours later.

McDonnell and his accomplice broke through the front door as the homeowner tried to fight them off.

They beat the man over the head with an imitation firearm made from two metal bars until he gave them keys to his car. McDonnell had also previously attacked a man with a machete and has been transferred within the prison system several times because he had come into conflict with other prisoners.