LONDON, England (CNN) -- Fifteen crew members of a South African Airways flight spent the night in jail after customs officials found marijuana and cocaine worth nearly half a million dollars hidden aboard a long-distance flight to London, British customs officials said Wednesday.
South African Airways said it has a zero-tolerance approach towards any criminal activity.
The 10 women and five men -- who include three pilots -- were detained on arrival from Johannesburg, South Africa, after customs officials found 50 kilograms (110 pounds) of marijuana and 4 kilograms (8.8 pounds) of cocaine in three pieces of baggage, HM Revenue and Customs said.
The drugs are estimated to be worth a total of £310,000 ($428,000), customs officials added.
Border agents arrested the crew at London's Heathrow Airport on suspicion of involvement in smuggling prohibited drugs into the United Kingdom, customs spokesman Bob Gaiger said. He said he was not able to disclose what led investigators to believe the suitcases belonged to the crew members.
Customs officials interviewed the crew members overnight, and all were released on bail Wednesday pending further inquiries, Gaiger said. They were not charged, according to the airline.
South African Airways said it launched its own investigation involving the airline's security and the South African Police Service.
"SAA has a zero-tolerance approach towards the use of the airline's services for any criminal activity," airline spokeswoman Robyn Chalmers said.