The Crime Branch of Mumbai police has launched a probe into the receipt of a letter by Mukesh Ambani, chairman of Reliance Industries Limited, (RIL), that threatened to harm him. The letter was allegedly sent by the Indian Mujahideen (IM).

An unidentified person on February 24 delivered a letter written in English at the company’s corporate office at Nariman Point in south Mumbai. The letter threatened to cause harm to Mr. Ambani and his 27-storey residence Antilia on Altamount Road, citing his proximity to Gujarat Chief Minister Narendra Modi, and his growing investment in Gujarat.

The letter demanded the release of Danish, allegedly an IM operative. The letter has threatened to cause harm to the richest Indian on the earth, if this demand isn’t met. The company’s senior officers on Tuesday met the Mumbai Police Commissioner Satyapal Singh, informing him of this development.

Joint Commissioner of Police (Crime) Himanshu Roy said the police had begun a search for the person who delivered the letter. “We have CCTV footage from the Reliance office, which will help us to identify the person. Only after identification of the person, we can comment on the case,” he said.

Authorities are also probing the identity of Danish, since the letter hasn’t specified it. It is believed that the reference is to Mohammed Danish Ansari, from Darbhanga in Bihar. He was arrested by the National Investigation Agency in January for allegedly providing shelter to the Bhatkal brothers in 2009, before they escaped to Pakistan.

The letter, threatening Mr. Ambani, has accused him of grabbing land belonging to the Waqf Board to build his residence. It also said that he had hurt the sentiments of minorities by investing heavily in Gujarat and supporting Mr. Modi.