Indian police are probing a threatening letter sent by militant Islamists to India's richest man, Mukesh Ambani, for supporting a hardline nationalist politician, police and reports said Thursday.
The Mumbai Mirror said Indian Mujahideen had threatened to harm the head of the Reliance Industries group for backing Gujarat Chief Minister Narendra Modi who is expected to make a bid to become premier in polls next year.
Reliance is a major investor in Gujarat and Ambani hailed Modi as a leader with a "grand vision" as well as calling him a "brother" at a major business conference in Gujarat in December.
The letter, delivered to a Reliance office in Mumbai, also accused Ambani of grabbing land belonging to a state-run statutory body to build his 27-storey residence in the city, believed to be the world's most expensive private home, according to the newspaper.
Police confirmed they were investigating the letter, without giving details of its contents.
"We got the letter yesterday and we're verifying all the facts and an inquiry is going on," Mumbai police spokesman Satyanarayan Choudhary told AFP.
Modi remains hugely controversial in India as he was in power in Gujarat when the state was engulfed by clashes between Hindus and Muslims. Two thousand people were killed, most of them Muslims.
Indian Mujahideen has been blamed for several recent deadly attacks in India, including the recent twin attacks in southern city of Hyderabad, which killed 16 people.