Shivaun Orton, 41, from Bangor, North Wales, and her Malaysian husband, Abdul Harris Fadilah, 46, were arrested on the border of Pahang and Terengganu states after the raid on 13 December.
Police are said to have found drugs including cannabis, ecstasy and amphetamines after searching the Ranting Resort, in Cherating, which is popular with backpackers. More than 225 grams of heroin was allegedly found nearby.
The couple, who have sons aged 14 and 16, are being held in Kemaman police station in Terengganu state. Possession of illegal drugs in Malaysia can carry the death penalty.