Fire crews came to the aid of more than a dozen police officers who were locked out of the station by faulty electronic gates.
Firefighters from the New Addington station took two minutes to solve the problem at Addington police station in Addington Village Road, and let the officers through the gates.
Vicki Hawkins, crew manager of New Addington fire station said the police officers were a bit embarrassed by the episode on Saturday, March 1.
Up to 15 officers and several patrol cars were unable to get through a set of electronic gates after the swipe cards used to get in failed to work.
Ms Hawkins said: "It made our morning.
"It took two minutes - we used a ladder and climbed over the gate to access a box on the other side.
"I don't think they had a ladder."
A total of five firefighters were called to the scene at 6.55am and left shortly afterwards.
A Metropolitan Police spokesperson said: "London Fire Brigade attended to assist access to the police station.
"There was a failure with swipe access.
"There was a fault."