Assisted suicide advocate Jack Kevorkian died in a Detroit area hospital following a short illness at the age of 83, according to a close friend and prominent attorney.

Kevorkian died at 2:30 a.m. Friday after being hospitalized at William Beaumont Hospital in Michigan since last month with pneumonia and kidney problems, his attorney Mayer Morganroth said.

An official cause of death had not been determined, but Morganroth said it likely will be pulmonary thrombosis.

"I had seen him earlier and he was conscious," said Morganroth, who added that the two spoke about Kevorkian's pending release from the hospital and planned start of rehabilitation. "Then I left and he took a turn for the worst and I went back."

Nurses at the hospital played recordings of classical music by composer Johann Sebastian Bach for Kevorkian before he died, Morganroth said.

Kevorkian was released from a Michigan prison in 2007 after serving eight years for second-degree murder. He claims to have assisted in at least 130 suicides.

In 2008, he ran for Congress as an independent, receiving just 2.7 percent of the vote in the suburban Detroit district. He said his experience showed the party system was "corrupt" and "has to be completely overhauled from the bottom up."

His life story became the subject of the 2010 HBO movie, "You Don't Know Jack," which earned actor Al Pacino Emmy and Golden Globe awards for his portrayal of Kevorkian. Pacino paid tribute to Kevorkian during his Emmy acceptance speech and recognized the world-famous former doctor, who sat smiling in the audience.