Prison chiefs have dismissed renewed claims that a biometric identity system at a Scottish jail failed so badly it let inmates have a free run.
The system uses a fingerprint and a Pin number
The issue was raised in a House of Lords exchange on biometric ID cards.
The Earl of Northesk, a Tory, said Glenochil Prison's fingerprint system had let prisoners access all parts of the jail, settling "old scores".
The Scottish Prison Service denied the claim, saying there had been a problem in September but that it was limited.
The Earl, an IT specialist, brought up the case of the fingerprint recognition system at question time, ahead of the Lords committee stage of the controversial Identity Cards Bill on Tuesday.
He said: "Within very short order of it being installed the inmates had circumvented the system and gained access to all parts of the prison, even to the extent of settling old scores."
But SPS spokesman Tom Fox said the allegation of inmates settling scores was "just not true".
He added: "We had a biometric system installed and there were problems with it about two months ago.
"The degree of sensitivity had been reduced below the required threshold and it wasn't as discriminate as it should have been.
"The system only allows access to certain parts of the prison, it only controls access within wings. Keys are used to access the whole prison."
Mr Fox said the system was already used in various prisons and required both a fingerprint and a Pin number.