A man who smears human excrement inside train carriages travelling through Croydon is being hunted by police.

British Transport Police have released CCTV images of the man they said has vandalised at least 30 trains since August, causing approximately £60,000 in damage and cleaning costs.

The disgusting criminal damage has also disrupted and led to the cancellation of several train services across south London.

Detective Constable Donna Fox said: "This is obviously a serious public health issue as well as being exceptionally anti-social. We need to locate this man as soon as possible.

"There is no particular pattern as to when he appears. He travels to various areas and at different times of the day and different days of the week and basically waits to be in part of a carriage by himself before he commits these offences."

She added: "On at least one occasion CCTV footage shows the man being disturbed by a passenger walking through a train. We are appealing for this man or anyone else who may have witnessed this man committing offences to contact us.

The police have warned the public not to approach the man if they see him but to call them or alert train staff immediately.

Anyone with information should call the British Transport Police witness appeal line on 0207 391 5275 or Crimestoppers anonymously on 0800 555 111.