A man was arrested in Mumbai for issuing threats to Reliance Industries Ltd (RIL) chairman Mukesh Ambani and his family, according to the local police.

The man, identified by the police as Vishnu Bhowmik, 56, made eight threat calls on a landline number at the Reliance Foundation Hospital in Mumbai' this morning, officials said. He is reported to have used different names while making the calls one of which was Afzal. 

The suspect was traced after the police identified the phone number from which he had made the calls. A case has been registered and the man is being questioned by the police.

A preliminary investigation suggests the caller is mentally unstable, news agency PTI quoted an official as saying.

Last month, the Supreme Court had ruled that Mukesh Ambani and his family in Mumbai can continue to have security provided by the central government, rejecting a petition challenging the provision.