An NHS worker was punched in the head and thrown off the Tube after he confronted three passengers for not wearing face masks.
The row erupted on the Circle Line when he noticed two men and one woman without the coverings.
One of the men punched the victim several times in the side of the head before throwing him off the carriage onto the platform at High Street Kensington station.
The group stayed on the service as it left the station at around 10pm on Saturday, October 3.
The victim suffered serious injuries, including a chipped jaw and three breaks to his eye socket.
Officers have released an image of a man who may have information to assist their investigation.
It is currently mandatory to wear a face covering on all forms of public transport, including trains, buses, coaches, ferries, the Tube and on board planes – unless you are exempt.
Exemptions include children under the age of 11 and those who are unable to wear a mask due to a physical or mental impairment or disability.
Those who do not comply with the rules could potentially face a £100 fine.
Get in touch with our news team by emailing us at [email protected].
For more stories like this, check our news page.