H Vasanthakumar was in critical condition after contracting severe pneumonia, doctors said.
Congress MP from Tamil Nadu's Kanyakumari, H Vasanthakumar, who had tested positive for the coronavirus, has died, hospital authorities in Chennai said on Friday.
The 70-year old leader was admitted to an Apollo Hospital in Chennai on August 10 with a coronavirus infection, the hospital had said.
He was in critical condition after contracting severe pneumonia and had been placed on ventilator support, doctors said.
"Despite all active medical measures, his condition deteriorated gradually due to COVID complications and he passed away today," the hospital said.
Fondly called Annachi or brother, he is survived by his wife, two sons and a daughter, a party spokesperson said.
A first-time MP from Tamil Nadu, H Vasanthakumar had also been elected MLA twice in the past from the Nanguneri assembly constituency and was the working president of the state Congress committee.
He also established Vasanth & Co, a chain of consumer electronics and home appliances stores and Vasanth TV, an entertainment satellite channel.
From his humble beginnings as a salesman, H Vasanthakumar went on to have his smiling face on billboards and ads for his vast retail chain across Tamil Nadu.
Born on April 14, 1950, the lawmaker was the brother of Tamil Nadu Congress veteran and noted Tamil litterateur Kumari Ananthan. Telangana governor Tamilisai Soundararajan is his niece.
H Vasanthakumar is the second lawmaker in Tamil Nadu to die of COVID-19. Earlier, DMK MLA Palakadai Anbazhagan had died after contracting the coronavirus.
President Ram Nath Kovind, Prime Minister Narendra Modi, Tamil Nadu Chief Minister K Palaniswami, who is Vasanthakumar's niece, Congress party leaders Rahul Gandhi, P Chidambaram and DMK president M K Stalin were among those who condoled the death.
Tamil Nadu Congress Committee President K S Alagiri said with his death, "a pillar of the state unit has fallen". As a mark of respect, Mr Alagiri announced a week-long mourning, adding party flags will fly at half-mast and all party events are being cancelled.
Makkal Needhi Maiam chief Kamal Haasan, actor Rajinikanth,PMK and MDMK leaders S Ramadoss and Vaiko were also among those who condoled the death.