A Mumbai court on Tuesday sent a man to police custody till August 20 for making death threats to Reliance Industries Limited chairperson Mukesh Ambani, The Indian Express reported.

Vishnu Vidhu Bhaumik, 56, was arrested on Monday from Mumbai’s Borivali area after he allegedly called multiple times on a helpline number of the city’s HN Reliance Foundation Hospital and issued threats to Ambani.

Bhaumik hails from Tripura and has been living in Mumbai for the past 26 years.

On Tuesday, the police sought 10-day custody of Bhaumik, saying that they want to find out why he made the calls. The public prosecutor said that the mentality behind threatening Ambani was a serious matter for the country.

However, the defence counsel told the court that Bhaumik was mentally ill and had been undergoing treatment since 2013, according to The Indian Express. The counsel contended that in view of his condition, Section 506(2) of the Indian Penal Code (criminal intimidation) should not be invoked against him, and only Section 504 (intentional insult to provoke breach of peace) should be applied.

Meanwhile, the police have seized Bhaumik’s phone and will send it for cyber analysis, The Times of India reported on Tuesday.

On Monday, the HN Reliance Foundation Hospital’s Chief Executive Officer Tarang Gianchandani told IANS that the medical facility received eight threat calls.

“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 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.