A Scotland Yard special constable shouted racial abuse at a rail worker after being accused of fare-dodging on a train from Sussex to London.

Off-duty Luke Smith, 27, rowed with staff on board a train between Gatwick and East Croydon stations.

The Metropolitan Police, which has been blighted by a wave of racism allegations in recent months, described his conviction for a public order offence as "appalling".

Smith, of Carey Gardens, Wandsworth, south London, was fined for the offence at Croydon Magistrates' Court but cleared of fare evasion.

A British Transport Police (BTP) spokesman said the incident took place in the early hours of October 5 last year.

Smith racially abused a 48-year-old member of rail staff on board the train.

The spokesman said: "BTP officers were called to the scene at around 3.15am and Smith was arrested.

"BTP launched an investigation, spoke to a number of witnesses and viewed CCTV footage.

"Smith was charged on Thursday November 3. At Croydon Magistrates' Court on Wednesday May 16, Smith was found not guilty of fare evasion and fined for a racially aggravated offence."

The officer has been suspended by Scotland Yard.

Commander Peter Spindler, director of professional standards at the Met Police, said: "This type of appalling behaviour will not be tolerated on or off duty from any member of our staff.

"We are referring this matter to the misconduct unit for further action against the officer."