Bob Barker died from Alzheimer's disease.

The beloved 'Price is Right' host passed away on 26 August aged 99 and a copy of his death certificate obtained by TMZ has revealed he was diagnosed with the degenerative condition "years" ago, though he never publicly spoke about his illness.

The legendary TV star - who hosted the iconic game show for a total of 35 years - was previously described as having passed away at his Los Angeles home from natural cause.

His representative confirmed in a statement: “It is with profound sadness that we announce that the World’s Greatest MC who ever lived, Bob Barker has left us.”

Bob - who was vegetarian for over four decades - suffered an injury in 2019 after taking a spill in his Hollywood Hills home, where he was treated by paramedics and not taken into hospital.

The previous year, Bob was hospitalised in Los Angeles twice within one month because of severe back pain.

The former host also went to the hospital in 2017 after hitting his head in a fall at his home.

Speaking about his long career, he admitted that he had "never" studied speech or aimed for a career on camera before he had been working for a local radio station and ended up as an announcer by chance.

He said during a speech at the Emmys in 2000: “I had never studied speech. I’d never studied drama. I had never been in a school play. I had never been before an audience and I was on duty there as an announcer. Ted Tucker, bless him, didn’t show up.

“I didn’t even have time to get nervous. I’m out there doing it live.”

A majority of Bob's estate will be divided up and donated to more than 40 different military charities and animal rights organisations.