Nigel Holness, London Underground's operations director, said:
"On Monday afternoon a Bakerloo Line train terminating at Queen's Park station mistakenly took one passenger, who had not alighted despite several announcements that the train was out of service, into the train depot."The passenger left the train and attempted to make his way back to the station, and was escorted back by the train driver."Every day there are thousands of train movements to and from depots and this type of incident is very rare given the procedures that are followed and safety systems we have in place.
"However, this can happen should a person not hear the three announcements that are always made before a train is taken out of service. In these circumstances anyone that is found will be escorted back to a station or depot."
More top news
A teenager who was mistakenly released from prison after he was arrested on suspicion of attempted murder has been detained by police.
Is your street among London's trendiest hotspots?
Some of the best stories from the past week on itv.com/london. Got a story? Email us at email@example.com