Pop singer Michael Jackson has died after suffering a heart attack, a US website has said.

Paramedics were unable to revive Jackson after receiving a call to his home in Los Angeles on Thursday, reported TMZ.com, a celebrity news website.

"We've just learned Michael Jackson has died ... Michael suffered a cardiac arrest earlier this afternoon and paramedics were unable to revive him," TMZ reported. 

"We're told when paramedics arrived Jackson had no pulse and they never got a pulse back," the report said.

There was no official confirmation of the reported death and spokespersons for Jackson could not be reached for comment.

A spokesman for the Los Angeles Fire Department had earlier told The Los Angeles Times that paramedics responded to a call from an address corresponding to Jackson's at 12.21pm (2021 GMT).

Officials at the UCLA hospital, where Jackson is believed to have been taken, were not immediately available for comment.