An engineer at Waterloo Station has died while working on the travelator.
Transport for London told Mirror Online that they are aware of the death and that British Transport Police are investigating but it is not thought to be suspicious.
A private ambulance was spotted at the station, which remains open, this morning.
A source at the station told the Mirror the man died working on a travelator which is part of the interchange between the Jubilee and the Northern/Bakerloo lines.
It is not clear what happened but a TfL spokeswoman confirmed he was working at the London station this morning.
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At 5.24am TfL Access wrote on Twitter: "Waterloo Station: No interchange between lines, due to a fault with the the travellator. Please exit the station and walk back in."
Two hours later a tweet from the Jubilee Line read: "Waterloo Station - A one way system has been implemented at this station due to an ongoing police investigation, customers are advised to avoid interchange where possible."
A full statement from Transport for London is expected later this morning.
British Transport Police have been approached for comment.
Waterloo station, also known as London Waterloo, is one of the busiest stations in London.
It is also the country's largest station in terms of floor space and has the greatest number of platforms.
