EMERGENCY services are investigating reports of a trespasser on the railway line.

The incident at Gatwick Airport means trains are running at a reduced speed through the station causing delays.

Disruption is set to continue until 10am.

A Southern Rail spokesman said: “Emergency services are on site but for everyone’s safety, while they investigate this incident, trains will run at reduced speeds in the area.

“As a central point of many Southern and Thameslink routes, please note this will affect many trains due to the length of the routes of many of our services.

“Alterations will take place, so please check journey planners or station boards if possible.”

At about 8.10am the spokesman said the "trespass incident had ended" and all lines have now reopened.

He said: "Trains may continue to be delayed whilst the service returns to normal.

"We anticipate a good service will be operating by 10am.

"Following a search by emergency services, trains are now running as normal.

"Some alterations will be made, to recover from the delays caused by this trespass incident."