Police in Spain are hunting a serial killer linked to the murders of at least four men he met on gay dating app Grindr.
All the deaths, which took place during the autumn, were attributed to natural causes during initial post-mortems but police are now re-examining the evidence, Basque newspaper El Correo reports.
Detectives working in Bilbao discovered money had been taken from the dead men's bank accounts and at least one had traces of date rape drug GHB in his body.
Investigators have suggested the men may have been drugged and their bank accounts raided after they met up for Grindr dates at their homes.
Detectives are also said to be analysing the deaths of another four men in the Basque city of Bilbao to see if they could have suffered the same fate.
The horrifying revelations on Wednesday were sparked by a complaint in December from a man who survived an attempt to strangle him.
He discovered a rucksack the strangler had ditched while fleeing during the resultant struggle had contained GHB and personal documents.
A police source told El Pais that the investigation was not being limited just to Bilbao, but probes were being carried out as far away as Madrid and Alicante.
"There could be a situation where, because they were initially treated as natural deaths, there was not enough evidence to accuse the alleged perpetrator of homicide, although there was robbery," the source told the publication.
Newspaper El Correo said the suspect is a man aged between 20 and 30.
