Conservative blogger, media publisher and activist Andrew Breitbart has died at the age of 43, according to his website.
He died of natural causes early today, the website says in a statement.
His death was confirmed by Joel Pollak, editor-in-chief of his website, who says he was at the hospital, the Associated Press reports.
Breitbart was an outspoken critic of the mainstream media. His efforts were behind controversial investigations that led to the resignations of former Rep. Anthony Weiner and former Agriculture Department official Shirley Sherrod.
He was lionized by his fans for his efforts at exposing government corruption and media bias, the AP says.