Police are investigating the incident on the Hammersmith and City line in east London yesterday at 3.30pm.

The horrifying attack happened on a Jubilee line train travelling between the Southwark and London Bridge stations, on Monday, June 30. Pictured: The person of interest

Police are investigating the incident on the Hammersmith and City line in east London yesterday at 3.30pm.

Group of men remove suspect from train after he shouted at people and waved his belt around

British Transport Police (BTP) believe the naked man, who has since been detained under the mental health act, was assaulted on the District line in east London .