Tata, 86, said on Monday he was undergoing routine medical investigations due to his age and related medical conditions.

A representative for Tata did not immediately respond to a request for an update on his condition today.

The sources, one of them close to the Tata family, and both with direct knowledge of his medical condition, did not give further details on the nature of his illness.

Tata has been admitted to Mumbai’s Breach Candy hospital, they said.

In a statement published on his social media profiles on Monday, Tata said he remained in good spirits and that there was no cause for concern.

Tata became chairman of the autos to steel conglomerate in 1991 and ran the group founded by his great-grandfather more than a hundred years ago until 2012.

He founded telecommunications company Tata Teleservices in 1996 and took IT company Tata Consultancy Services public in 2004.

After stepping down, he was conferred with the title of chairman emeritus of Tata Sons, Tata Industries, Tata Motors, Tata Steel and Tata Chemicals, the company website says.