There was severe disruption on the Central line after a fatality on the tracks.
Officers and paramedics were called to Holland Park station at about 1.30pm on Friday following reports of a casualty on the tracks.
A person was found at the scene and pronounced dead by paramedics, a spokeswoman for British Transport Police said.
"The incident is not being treated as suspicious and a file will be prepared for the coroner," she added.
The force is now working to identify them and inform their family.
There was no service between Marble Arch and White City while emergency services remain at the scene. There are severe delays on the rest of the line.
"Tickets are being accepted on London buses, TFL Rail, Paddington to Hayes and Harlington and Liverpool Street to Shenfield," a TfL spokesman said.
"Chiltern Railway is accepting tickets Marylebone to West Ruislip, Great Western (Greenford branch) DLR, London Overground and Greater Anglia via reasonable routes."
