Bangkok gas deliverymen have been told to stop wearing Spider-Man outfits but that it's okay for them to dress as monkeys.

Gas shop owner Narongwit Suthiviriyakul says business has almost doubled in the 10 days since his delivery team started wearing the outfits.

Lawyers representing Bongkoch Publishing Company - the Thai agent for Marvel Enterprises which publishes Spider-Man comics - have threatened legal action.

Licensing manager Sirijan Phipitrangsee says the deliverymen can wear monkey suits "because monkeys don't have intellectual property rights."

The Nation says orders for supplies of cooking gas at the shop have increased from 30 to 50 a day since the gimmick started.

Narongwit says he was unaware of the copyright law when he launched the promotion.