Steven Kaye, 32, was chased by security officers and detained within Leeds Crown Court during his sentencing for drug offences in September 2021, where he was given a 67 month custodial term.
Officers entered Kaye's cell at around 6pm on December 10, 2021 at HMP Wealstun, where he was serving his sentence.
Leeds thunderstorms warning as Met Office shares latest weather forecast
Rage Against The Machine pull out of headline slot at Leeds Festival
Lamborghini pictured with car on top of its bonnet at busy Leeds junction following crash
York Road incident: Police appeal after pedestrian killed in crash outside Leeds Dogs Trust
Leeds Bradford Airport: Full statement on August security staff strike
Prosecutor Damian Broadbent told the court Kaye "appeared to be concealing something".
Kaye, of Stanks Avenue, Leeds, was x-rayed by body scanners and officers discovered he had a mobile phone "secreted".
He was taken to a segregation unit where he later "volunteered" the phone to officers, the prosecutor told the court.
Kaye was charged with possession of a mobile phone in prison.
He pleaded guilty at Leeds Magistrates' Court.
Kaye has 27 convictions for 54 previous offences, the court was told.
In mitigation, Stephen Smithson said Kaye pleaded guilty to the offence at the Magistrates' court at the first opportunity.
Sentencing Kaye, Judge Simon Phillips QC said "time and time again" the courts had identified cases where the impact of mobile phones in prisons had been a factor.
Kaye was given a 10 month custodial sentence which will run consecutively with his current 67 month term.