POLICE want to speak to this man after a Forest Hill station staff member was struck so hard he fell to the ground.

Detective Constable Ian Garden from British Transport Police’s Workplace Violence Unit explained: "Around 4.50pm on July 24, a man came off a northbound train at Forest Hill station and walked up to the barrier line, where he struck a member of staff with such force it caused him to fall on the floor.

"The force of the fall caused the victim to sustain a serious injury to his knee, which will require surgery."

Police have now released a series of CCTV images showing a man they want to speak to in relation to the incident.

Det Con Garden said: "This was a really nasty assault on the victim, who was simply trying to do his job and has found himself badly injured as a result.

"Staff should be free to carry out their duties without fear of violence and abuse such as this and we are determined to find the person responsible."

If you can help call police on 0800 40 50 40 or text 61016 quoting reference B1/LSA of 02/08/2013. Alternatively, call Crimestoppers, anonymously on 0800 555 111.