Shane Warne's manager says the famous cricketer was alone and watching cricket when he suffered a suspected fatal heart attack in Thailand.

Shane Warne was sober and alone, watching cricket, when he suffered a suspected fatal heart attack, his manager says.

The Australian cricket legend's long-time manager James Erskine says Warne was just days into a three-month spell from work when he died at a resort in Thailand.

Erskine, who said Warne detested and never took drugs, was found by friends who were holidaying with the famous ex-cricketer at a villa on the Thai island of Koh Samui.

"Shane had sort of decided he was going to have three months off," Erskine told Fox Cricket.

"In fact, he wanted a year off and I said: 'there's no way you can have a year off, they would've forgotten you by a year'.

"So he decided to have three months off.

"This was just the start of it and they'd only arrived the day or night before."

Erskine said Warne's friend and business manager Andrew Neophitou, staying in the same villa, had gone to Warne's room.

"They were going to have a drink at 5pm (Friday, local time) or go and meet someone to go out and have a drink at 5pm," he said.

"And Neo knocked on his door at 5.15pm because Warnie is always on time.

"He went in there and said 'come on, you're going to be late' and then realised something was wrong.

"And he turned him over and gave him CPR and mouth-to-mouth, which lasted about 20 minutes and then the ambulance came.

"They took him to the hospital, which was about a 20-minute drive, and I got a phone call about 45 minutes later saying he was pronounced dead."