The septuagenarian is being treated at an isolated intensive care unit, he said.

“Mr Mitra was hospitalised this afternoon after he tested positive for Covid-19 as well as influenza. He has several comorbidities, but he is stable. Doctors are constantly monitoring his condition,” the official told PTI.

The economist, who is currently the principal chief advisor to Chief Minister Mamata Banerjee, has been keeping unwell for some time.