Betty White suffered a stroke six days before dying “peacefully in her sleep” at the age of 99, according to reports.

The beloved actress, who was best known for playing character Rose in TV sitcom Golden Girls, passed away on New Year’s Eve, just three weeks away from celebrating her 100th birthday.

White’s cause of death has been listed as a cerebrovascular accident, the official term for a stroke, report TMZ, who obtained a copy of her death certificate.

While a stroke can cause lasting brain damage and long-term disability, sources told the US outlet that the Mary Tyler Moore Show star was “alert and coherent”.

Confirming that White had suffered a “mild stroke,” an insider reiterated to People that she “died peacefully in her sleep,” as per the original statement from White’s agent following her death on December 31.

A number of famous faces flocked to social media to pay tribute to White, including actor Ryan Reynolds, 45, who starred alongside her in 2009 comedy movie, The Proposal.

Taking to Instagram, he wrote: “The world looks a little different now. She was great at defying expectation. She managed to grow very old and somehow, not old enough. We’ll miss you, Betty. Now you know the secret.”

Meanwhile, US President Joe Biden hailed White as a “cultural icon,” over on Twitter.

“Betty White brought a smile to the lips of generations of Americans. She’s a cultural icon who will be sorely missed. Jill and I are thinking of her family and all those who loved her this New Year’s Eve,” the President tweeted.