It was fortunate no-one phoned prison inmate John Minchinton.
For when warders at HMP Bristol conducted a search of the cells he had a mobile phone hidden between his buttocks.
Regardless of the device remaining silent it eventually came to light.
Minchinton, 42, of no fixed address, pleaded guilty to possessing a prohibited item in prison.
Judge Julian Lambert handed him a four-month jail term to run within an existing sentence.
Richard Posner, prosecuting, told Bristol Crown Court prison staff conducted a cell search at HMP Bristol at 8.45am on May 13 last year and found Minchinton with the phone.
Minchinton said he came into possession of it the night before.
There was no evidence of the phone being used for criminal purposes, the court heard.
Will Parkhill, defending, said that, in the main, his client was a model prisoner who had enhanced status and was trusted.
Mr Parkhill said that, having been transferred to HMP Exeter, Minchinton had preserved enhanced status and was working as a listener as well as in the prison servery.
Mr Parkhill told the court: "He knows the way to get on in prison is to be a model prisoner.
"He let himself down.
"There is no evidence of use of the phone to facilitate crime in the exterior world."
