Everton footballer Andy van der Meyde is recovering in hospital after claiming his drinks were spiked during a night out in Liverpool.
Detectives are awaiting results of a blood test
Ambulance crews were called to the 26-year-old's home in Bebington on the Wirral in the early hours after he suffered breathing problems.
Following claims the Dutchman's drinks were spiked, police spoke to staff and viewed CCTV footage from two bars.
Detectives said their investigations into the incident are continuing.
They are awaiting the results of a blood test as the player recovers in Arrowe Park Hospital.
A police spokeswoman said: "We were called to an address on the Wirral from a woman who claimed that her partner had had his drinks spiked.
"We are looking at CCTV taken at city centre bars and investigations are continuing."
A spokesman for Everton FC confirmed that van der Meyde had been admitted to hospital on Monday morning suffering from illness.
"His progress is currently being monitored by hospital staff," he said.
"The club will be making no further comment on the incident until after Merseyside Police has concluded its ongoing investigation into the circumstances surrounding Andy's admission into hospital."
Van der Meyde, who has suffered a number of injury problems, signed for Everton last August and has made 11 appearances for the club.
He began his career with his hometown club of Vitesse Arnhem and joined Ajax in 1997 at the age of 17.
Earlier this year the player was forced to deny rumours he was an alcoholic.
In an interview with the club's website, he said: "I've heard people say that I drink a lot and that I have been going out all the time.
"But we are all human and we all have problems. When I was out injured things were just so difficult.
"I was frustrated with everything and I wanted to forget things. But I am not an alcoholic."