The cause of Ozzy Osbourne's death was revealed after the rock icon's funeral.

The 76-year-old Black Sabbath frontman, who was diagnosed with Parkinson's disease in 2019, died on July 22 of a heart attack.

The death certificate, filed by his daughter Amy at a London registry office, was obtained by The New York Times.

"The certificate states that Osbourne died of '(a) cardiac arrest outside of a hospital (b) acute myocardial infarction (c) coronary artery disease and Parkinson's disease with autonomic dysfunction (concurrent causes),'" the newspaper reported.

When Ozzy's family announced his death, they did not disclose the cause, although it was later reported that an air ambulance had arrived at his Buckinghamshire estate, which is classified as a Grade II listed building, on the day of his death.

The Thames Valley air ambulance landed in a field near Welders House on the morning of July 22 at around 10:30 a.m.

Last week, Ozzy was buried next to a "beautiful" lake in the park of his family estate.

The Prince of Darkness received a fitting send-off in a public procession through the streets of Birmingham on July 30, during which thousands of fans, as well as Ozzy's family, paid their respects.

The music legend was buried a day later at his family home — which he and his wife Sharon bought in 1993 — in an "incredibly emotional" private ceremony for 110 of his loved ones, The Sun reported.

A wreath with an inscription was placed at the water's edge during the ceremony, which was attended by Sharon and his children Jack, Kelly, Amy, and Louis, who is Ozzy's son from his first marriage to Thelma Riley.

Among the mourners were stars such as Ozzy's Black Sabbath bandmates, James Hetfield of Metallica, Yungblud, Sir Elton John, and Marilyn Manson.

Other notable guests included Ozzy's guitarist Zakk Wylde and Slipknot frontman Corey Taylor.

"Ozzy wanted his final resting place to be at home, and he is buried in a beautiful spot on the shore of the lake," said a source close to the family. | BGNES