Reliance Industries Limited chairperson Mukesh Ambani and his family have received death threats, the Mumbai Police said on Monday.

The calls were made to Reliance Foundation Hospital from an anonymous number. After tracing the caller, a mentally ill man was detained, according to an unidentified official, according to PTI.

Reliance Foundation Hospital Chief Executive Officer Dr Tarang Gianchandani told IANS that the medical facility received eight threat calls consecutively.

“We immediately complained to the police,” she said. “We have also initiated our own internal security measures and have full faith in the Mumbai Police.”

Security at Ambani’s Mumbai home, Antilia, has also been beefed up along with the family’s private security detail.

Ambani and his family are provided with Z+ security cover, under which 58 personnel of the Central Reserve Police Force guard them round the clock. His security level was upgraded from the Z category in 2013 after the Union home ministry carried out a review of threat perception.

In July, a petition was filed against the security in the Tripura High Court, which asked for the review file about the threat perception to the businessman and his family. However, the Supreme Court dismissed the petition and asked the Centre to continue providing security cover to the Ambanis.