A prison inmate was found with an illicit mobile phone when staff carried out checks, Lincoln Crown Court was told.
Robbie Northridge, who was serving a 12 month sentence on B Wing at Lincoln Jail, during checks on the evening of February 19 this year.
Phil Howes, prosecuting, told the court: "Prison officers using a mobile phone detector picked up a strong signal on B Wing outside the defendant's cell.
"They entered the room despite their entry being hindered by a blockade. The defendant was found trying to conceal something in his boxer shorts. The item was a small mobile phone. A charger was also found in the cell."
Northridge, 26, of Mansfield Road, Nottingham, admitted unauthorised possession of a mobile phone in prison. He was jailed for six months.
Neil Sands, in mitigation, said Northridge was released from his original sentence on May 21 and since then has fully engaged with the probation service and obtained full-time work for the first time in his life.
"This was the first pay slip he has ever received. There was a sense of pride when he said that to me," he said.
Mr Sands said sentencing of Northridge should be deferred to see if he continued to make progress with his life or, alternatively, he should be given a suspended jail sentence.
But Judge Simon Hirst said a prison sentence had to be imposed for the offence.
The judge told Northridge: "The possession of mobile phones in prison is particularly serious because it gives unmonitored access to people outside of prison.
"The message has to go out that having a mobile phone in prison will only result in a custodial sentence."
