Story highlights Vitaly Churkin died February 20, one day before he was to turn 65

NYC official says he died of a heart attack

(CNN) Russian Ambassador to the United Nations Vitaly Churkin died of a heart attack, with no signs of foul play, a senior New York City official told CNN, citing a medical examiner's autopsy.

The city's Office of Chief Medical Examiner said earlier on Friday that it would not publicly disclose the cause and manner of Churkin's death because of diplomatic immunity laws.

"As outlined in formal requests from the United States Department of State, Ambassador Churkin's diplomatic immunity survives his death. Further questions concerning this matter should be directed to the United States Department of State," Julie Bolcer, a spokeswoman for the medical examiner, said.

Churkin died in New York City on February 20, one day before his 65th birthday.

Churkin spent more than 40 years in the diplomatic service and headed the Russian Mission to the United Nations for more than a decade.

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