The death of a woman from south London on the island of Ibiza was "almost certainly" caused by drugs, Spanish police have said.
Jodie Nieman, 20, from Croydon, suffered a heart attack in the south-east of the island early on Wednesday.
She had been on a night out at the Space club in the Playa d'en Bossa resort when she fell ill.
Officers were "almost 100% certain" this was because of drugs, a Guardia Civil spokesman said.
Results from a post-mortem examination on the British tourist are expected to be released on Friday.
Miss Nieman had been staying in a flat in the resort with a group of female friends.