Flights had to be diverted and passengers are facing delays after the runway at Gatwick was closed to all flights because of a spillage.
Incoming flights were forced to remain in the air and dozen were diverted after the oil spillage which happened at around 10.30am on Monday.
The runway re-opened just after 11.30am. A spokesman told HuffPost UK around 12 flights were diverted while delays to departures would continue.
He said such a spillage does "occasionally" happen and triggers safety checks to ensure the runway can take planes. He could not comment on the cause.
He said: "“Following the earlier closure of the runway, flights recommenced at 11:38am.
The runway closure has caused some flights to be diverted to other airports in the area and there will be delays to some departing flights.
"Friends and family waiting for passengers should contact the relevant airline for the latest information.”