London Old Street station
Police were called to London's Old Street stations after a body was found on Sunday, 21 May 2017. Reuters

A body has been found in London's Old Street underground station in what police describe as "unexplained" circumstances.

British Transport Police were called to the station at 1.27am on Sunday (21 May) after receiving reports that a body had been discovered.

The busy station was closed throughout Sunday morning and into the afternoon as police investigated the finding.

A spokesman for British Transport Police said: "We were called to Old Street underground station at 1.27am this morning to reports that the body had been found.

"The death is currently being treated as unexplained and the station is closed while investigations continue."

Both the Northern Line and Great Northern services were disrupted by the closures, but services had resumed shortly after 1pm.

A spokesman for National Rail said: "The police are attending to an incident at Old Street on the London Underground station, and have closed the station for a short while.

"Network Rail and Great Northern are working with the Police to reopen the station as quickly as possible. Whilst this incident is ongoing, our services are not stopping at Old Street.

"We are sorry for the problems this disruption will cause you."