Court appearances were delayed yesterday after security guards accidentally got trapped in jail cells.

Custody staff from security firm Serco spent six hours stuck inside the cells at Hendon Magistrates Court, in The Hyde, which are usually meant for prisoners awaiting their hearings or trials.

Court hearings had to be postponed and all prisoners were diverted to Willesden Magistrates Court as engineers worked to free the guards.

The issue occurred when the custody suite safe that contains the keys to unlock the external doors of the cells failed.

No prisoners were inside the cells at the time.

Serco’s contract director David Holdsworth said: “Serco staff check the security and safety of cells and custody suites in all courts every day.

“On this occasion, while staff were inside the custody suite the safe that contains the keys to unlock the external doors of the custody suite failed.

“Our procedures were immediately followed and all remaining staff and prisoners were diverted to other courts and all court hearings were completed.”

A statement from the HM Courts & Tribunals Service said: “Contingency plans were implemented and custody cases transferred to Willesden Magistrates' Court."

The safe has been repaired and Hendon Magistrates court reopened the following morning.