There were severe delays on the Bakerloo line this morning after someone fly-tipped a mattress onto the tracks.
The mattress was dumped on the tracks near Kensal Green station.
Transport for London (TfL) labelled the mattress an "obstruction" in a statement.
It said: "There are now severe delays between Queen's Park and Harrow and Wealdstone due to obstruction on the track earlier at Kensal Green.
"There is a good service on the rest of the line."
Elsewhere, the London Overground was part suspended between Romford and Upminster, and was running with severe delays between Watford Junction and Euston, also due to an "obstruction".
There were also minor delays on the Jubilee line.
