Officers from the National Police executed search warrants on lockers belonging to the 66-year-old doctor and his deceased colleague at the Costa del Sol Hospital, where both were employed.

Detectives suspect the hospital-use-only anaesthetic propofol - found at the scene - was stolen from the medical facility.

The locker searches come as police uncover hundreds of hotel and guesthouse bookings across Malaga province registered in the doctor's name.

According to investigators, official registry logs show the suspect checked into rooms with various male and female companions despite residing locally.

The investigation began on Thursday 1 October, when the doctor alerted emergency services after waking up to find his colleague uncommunicative inside room 113 of a Marbella hotel.

Upon arrival, police found the doctor waiting outside before he escorted officers to the room. Paramedics pronounced the 56-year-old nurse dead at the scene.

Investigators seized used syringes, drug vials, and additional prescription medicines - including propofol and morphine chloride - from bedside tables, a handbag, and the doctor's vehicle parked outside.

In statements to police, the doctor admitted to administering propofol via an intravenous line inserted into the nurse's jugular vein, claiming she had also injected him before both fell asleep.

Following his court appearance, the investigating judge granted provisional release subject to precautionary measures, including a travel ban and the surrender of his passport.

The magistrate ruled out a flight risk as the suspect had called emergency services himself and evidence at the scene had been secured.

However, National Police detectives maintain the case should be treated as suspected reckless homicide (homicidio por imprudencia grave).

Investigators argue that given his medical expertise, the doctor was fully aware that administering intravenous general anaesthesia outside a clinical environment without monitoring equipment posed a direct threat to human life.

Due to the intimate relationship between the two healthcare workers, the investigating court has referred proceedings to the specialist Gender Violence Court in Fuengirola to review potential domestic violence jurisdiction.

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