UPDATE: After being rushed to the hospital, his life support was turned off, and CBS News quoted a Los Angeles Police Department source confirming his death.
However, the police report has been refuted and TMZ.com says he is "clinging to life". Which they explained in a series of tweets below:
The 66-year-old 'Anything That's Rock & Roll' singer is said to have been rushed to UCLA Santa Monica Hospital on Sunday night (01.10.17) after EMTs arrived at his home in Malibu to find him unconscious.
According to gossip website TMZ, a source said the legendary musician was found "unconscious" and "not breathing", although it was said that a pulse was found when medical professionals arrived at the property.
An updated report later read: "We're told after Petty got to the hospital he had no brain activity and a decision was made to pull life support."
Last week, the singer concluded his tour - which began in April earlier this year - at the Hollywood Bowl, and he previously admitted the run on the road would likely be his "last big one".
He told Rolling Stone: "We're all on the backside of our 60s... I have a granddaughter now I'd like to see as much as I can. I don't want to spend my life on the road. This tour will take me away for four months. With a little kid, that's a lot of time."
Along with his group, Tom Petty and the Heartbreakers became stars in 1976, going on to have a string of hits over a number of decades.
These included the likes of 'American Girl, 'Refugee' and 'I Won't Back Down'.
He also spent time as a member of The Traveling Wilburys in the 1980s, and the supergroup boasted Bob Dylan, Roy Orbison, George Harrison and Jeff Lynne amongst its members.