Problems on the line between Embankment and Waterloo have caused severe disruption to commuters this morning with services suspended between Piccadilly Circus and Elephant and Castle.
TfL said: “There is no tunnel collapse on the Bakerloo line. Our engineers are on site and we are assessing the situation.”
Reports from passengers and from train drivers to the RMT union initially blamed the incident on a tunnel collapse.
Tfl said the problem was caused by “an obstruction in a tunnel at Embankment”.