Wrestler and film actor Dara Singh was admitted to a city hospital on Saturday evening, his family members said.
The 83-year-old was admitted to Kokilaben Hospital in suburban Andheri.
"He is serious. There is blood clot in his brain or he has suffered heart attack...we are not sure what has happened. We have been told that he is under observation for 24 hours," his son, Vindu Dara Singh said.
Singh was last seen in Imtiaz Ali's hit film, 'Jab We Met' (2007) as Kareena Kapoor’s grandfather.