Toronto Mayor Rob Ford reacts on the podium during his campaign launch party in Toronto, in this April 17, 2014 file phto. [Photo/Agencies]

TORONTO - Former Toronto Mayor Rob Ford, who became controversially known for his drug and alcohol abuse while in office, has died after battling cancer for years, his office confirmed Tuesday.

The 46-year-old sitting Toronto city councillor had been undergoing treatment for an aggressive form of cancer that had recurred despite surgery and several rounds of chemotherapy.

In a statement confirming Ford's death, his chief of staff Dan Jacobs said that "over his decade and a half in municipal politics, Ford won a devoted following for being a straight talker who championed the average taxpayer."

Canadian Prime Minister Justin Trudeau offered his condolences. John Tory, who replaced Ford as mayor, called Ford "a man who spoke his mind and who ran for office because of the deeply felt convictions that he had."

During his tumultuous 2010-2014 tenure as mayor of Canada's most populous city, Ford admitted to smoking crack cocaine, buying illegal drugs and driving after drinking alcohol.

Ford dropped out of the reelection campaign in September 2014 when he was diagnosed with pleomorphic liposarcoma, a rare form of cancer found in soft, fatty tissue of the body, after he was admitted to a hospital with abdominal pain.