A prison warden has been sacked for getting too close to prisoners through the social networking website, Facebook.

An investigation into Nathan Singh, 27, who worked at HMP Leicester in Welford Road, started after he was suspected of supplying inmates with mobile phones and other banned items.

A disciplinary hearing heard there was no evidence of Singh smuggling anything into the prison, but he was friends with 13 criminals through Facebook.

Pictures on the website even showed him socialising with a criminal who was later jailed for 24 fraud offences.

Another of his Facebook friends stabbed a man to death outside a nightclub in Leicester in 1995.

A third was jailed for two years for affray, while a fourth was given five years for drugs offences and conspiracy to pervert the course of justice.

Singh has now been dismissed for gross misconduct.

Simi Sethi, spokesman for the Ministry of Justice, said Mr Singh had broken the prison's strict rules for staff.

He said: "He had been associating with serving and former prisoners, outside the course of his employment and without authority.

"We take inappropriate relationships with prisoners very seriously and staff who break rules are liable to be dismissed.

"We carry out thorough checks when we recruit prison officers.

"We work to create and support a culture which values integrity above all."

Giving evidence at the disciplinary hearing, Singh said he knew the criminals from school or playing football.

He said: "Sometimes when I logged on to my Facebook site there would be 20-odd friend requests and I just accepted them.

"Sometimes I didn't even check them. I realise now it might have been naïve in the job I do."

However, the investigation, launched five months after Singh joined the Prison Service in January last year, found he had been in phone contact with seven of the 13 criminal friends on Facebook.