Richard Simmons’ cause of death under investigation

Richard Simmons’ official cause of death is being investigated, the Los Angeles Police Department has said.

The legendary fitness instructor died on Saturday — just one day after his 76th birthday.

The case was deferred by the Medical Examiner’s Office in Los Angeles, which has called for a further probe, People reports.

The examination, which includes additional testing, can take up 3 months until an official ruling is determined.

Police and fire officials were dispatched to the health guru’s LA home after receiving a call from Simmons’ housekeeper Saturday morning, TMZ first reported.

He was pronounced dead at the scene. Police told the outlet that there was “no foul play involved.”

Simmons reportedly refused medical help after suffering a fall the night before he was found dead.

Law enforcement sources told TMZ that Simmons had fallen in his bathroom Friday night — which happened to be his 76th birthday — before his housekeeper helped him up and tried to get him medical help immediately.

However, he reportedly declined as he wanted to stay home on his birthday, sources told the outlet.

He then told his housekeeper that Simmons, who reportedly felt dizzy before the fall, said he would consider seeing a doctor the following day.

However, at around 10 a.m. the aerobics instructor was found unresponsive on the floor next to his bed.

Insiders told the outlet that Simmons showed no signs of injury after the accident.

Simmons, who revealed in March he had been diagnosed with skin cancer, said he felt “good” and was “grateful” to be “alive” in a rare interview published just one day before his death.

“I feel good! I am grateful that I’m here, that I am alive for another day,” Simmons told People last week. “I’ll spend my birthday doing what I do every day, which is to help people.”

Simmons, who had not been seen out in public for a decade, told the outlet that he missed his fans as much as they missed him.

“I know people miss me. And you know what? I miss them, too. But I’m able to reach them through phone calls… and through emails,” he said. “And I do leave the house sometimes. But I’m in disguise.”