A group of men accused of an attack which left a British holidaymaker in a coma may face "inhumane and degrading" treatment if extradited, an appeal hearing was told.

The men, who are accused of a serious assault on Robbie Hughes, 28, were extradited by District Judge Caroline Tubbs at Westminster Magistrates Court in February.

But yesterday lawyers asked the High Court to overturn the decision after "new evidence" showed the Greek jail the men could be sent to was "drug ridden, mice-infested and insanitary".

Former Sutton United and Croydon Athletic footballer Mr Hughes, of Wallington, now suffers from a brain injury and ten-year memory loss because of the assault on June 17 2008 in Malia, Crete.

Curtis Taylor, 20, Daniel Bell, 21, Sean Branton, 20, all from Horley, Benjamin Herdman, 20, from Worth, Sussex and George Hollands, 22, from Reigate in Surrey, are fighting extradition over the attack.

At the High Court their counsel, Alun Jones QC, cited the case of Andrew Symeou, who was held in a Greek jail for 11 months after being accused of manslaughter in Zakynthos in 2007 and finally granted bail on June 4 this year.

Mr Jones read a statement from Mr Symeou's Greek lawyer George Pyromallis, who described a "horrifying state of affairs" at the prison where inmates were in continuous danger of "brawls, riots...and rapes".

Mr Jones read: "...conditions become worse for those who are not Greek prisoners and cannot speak Greek".

He also read a statement from Mr Symeou who said he was "treated like an animal".

Mr Jones read: "I heard one night a man crying out in agony when being raped. There are mice and cockroaches everywhere."

Mr Jones said the men could be refused bail and forced to wait for up to 18 months for a trial to begin because they were "foreigners" and had no address in the country.

He said: "It is my submission that nobody could possibly make any other conclusion that what Mr Symeou was subjected to was inhumane and degrading treatment.

"The treatment of Mr Symeou demonstrates that there is a strong probability that these defendants will be treated in the same way.

"We submit this is a powerful and compelling case which requires this court to protect these people."

On behalf of the Greek prosecutor Hugo Keith QC said Mr Jones was making a “general presumption” on “general evidence”.

He said the evidence missed the threshold for Article 3 of the European Convention on Human Rights which he said ”deals with the most severe ill treatment”.

Mr Keith said the risk of human rights violations must be “real” not “fanciful” and ECHR'S Grand Chamber had no recent finding of violations of Article 3 in Greek jails.

He said a foreigner having a case heard in the UK might also be refused bail, if he had no address in the country and was likely to abscond.

He said: “While the conditions which Mr Symeou describes may raise some issues, it is not clear there are any systemic issues at all.

“Imperfect prison conditions are also sometimes a feature of all prisons in all EU countries.”

Mr Keith also said the witness statements were “clearly available” to the appellants in the magistrates court proceedings and there was no reason why they could not have been served in February.

He said: “If the clients had been genuinely concerned about human rights in Greece they could have...referenced NGO material and Amnesty International reports.

“We say their evidence could have been prepared with due diligence.”

The President of the Queen's Bench Division, Sir Anthony May, and Mr Justice Blair, reserved their decision on the five's challenge until a later date.

A sixth man, Joseph Bruckland, 20 from Hookwood, Surrey, will have a separate hearing of the same case.