Rajinikanth has been admitted to hospital in Hyderabad over "severe fluctuations" in his blood pressure, a statement said.
The mega-star is in Hyderabad for the shoot of his film "Annaatthe" but it was cancelled earlier this week after four members of the crew tested positive for Covid.
According to a statement by Apollo hospitals, Hyderabad, Rajinikanth had tested negative for Covid on Tuesday.
"Though he did not have any symptoms of COVID-19, his blood pressure showed severe fluctuations and needed further evaluation for which he has been admitted to the hospital. He will be investigated and monitored closely in the hospital till his blood pressure settles down before being discharged," the statement said.
Apollo added that apart from fluctuating blood pressure and exhaustion "he did not have any other symptoms and is hemodynamically stable".
Rajinikanth had in October admitted that his doctors had advised him to take extra care as his immune system was weak after a renal transplant, which made him more susceptible to the coronavirus. The doctors had reportedly advised the veteran actor that a vaccine was the only solution and they were not sure if his body would even accept it.
The actor put out the clarification after a leaked letter, said to be written by him, set off speculation that he was reluctant to join politics because of his health. "The letter is not mine but the information on my health and doctors' advice is true," Rajinikanth had said in a statement.
Last month, Rajinikanth consulted with his outfit and declared he had decided to enter politics and launch his party, which would contest the Tamil Nadu election due in four months. "It is now or never," he said, promising a miracle in the polls.
Sources close to the 70-year-old had earlier said he would return to Chennai in two days for his New Year's Eve announcement of the launch date.
The plan is for two leaders of his "Rajini Makkal Mandram" outfit to launch on January 4 a two-week tour of Tamil Nadu and visit every district to oversee the party's preps on the ground, including setting up booth committees. After their return, Rajinikanth is to formally launch his political party on the third or fourth week of January. (NDTV)