Commuters are facing disruption on the Brighton Mainline this morning (June 7) after an engineering train broke down between Gatwick and Purley.
Southern Rail warned passengers to expect delays until at least 10am.
A Southern Rail spokesperson said: “Earlier this morning, a maintenance train carrying out overnight engineering works had broken down.
“Following on from this the unit leaked a large amount of oil onto the tracks.
“A rescue train was sent to remove the defective unit. Although the line is now clear the oil needs to be removed from the tracks.
“The environmental agency also need to attend due to the content of the spillage.”
UPDATE: At 10.15am, Southern said: “All lines have now reopened following a broken down engineering train near Gatwick
“Knock-on delays are likely until at least 1pm.”