Have-a-go shopkeepers have criticised police after they performed a citizen's arrest on a suspected thief only to see the police let him go.

Anthony Cheke, of the Inner Bookshop, and Stuart Sylvester, of Sylvester's hardware shop, in Magdalen Road, in East Oxford, arrested the man after they suspected he had stolen staff members' mobile phones.

A day after the suspected thefts, Mr Cheke said the man was seen snooping around in another shop, so they arrested him and called the police.

He was then taken to a police station. Mr Cheke said he felt that with the evidence the shopkeepers had, they thought the police would at least search the man's home for stolen goods.

He added: "The duty officer ordered his immediate release and refused even to ask an inspector for permission to search. So this brazen thief is freed to carry on stealing, knowing that as long as he's not actually caught, the police can't won't touch him."

He said the offender then returned, threatening to kill them all.

Mr Cheke said: "Because we had impounded his bike, he started threatening us within earshot of the policeman, who gave him a warning."

Mr Cheke said the man had stolen a mobile phone from a rucksack in the kitchen of his shop, when he was spotted wandering out of the shop's basement.

He said: "He had been seen the previous day upstairs, wandering about in one of our offices."

Mr Sylvester said his mobile telephone was taken the previous day, when it was believed the thief had been upstairs in his shop.

He said: "He was prowling around here when my dad caught him round the back of the counter. He stole my telephone out of my jacket and had the audacity to come back again."

Police spokesman James Clements said: "Police officers were called by a shop owner who had detained a man he believed responsible for the theft of a mobile phone. An officer must have reasonable grounds for suspecting that someone has committed the offence to en- able them to arrest someone.

"In this case there was insufficient evidence against the man detained and he was released."