Veteran actor Dara Singh, who was hospitalised two days ago after suffering a cardiac arrest, is "extremely critical", the hospital authorities said here this morning. "He is extremely critical. He is still on ventilator and needs high level of oxygen. His kidneys are not functioning well," said Dr Ram Narain, COO, Kokilaben Ambani Hospital. The 83-year-old actor is known for roles in films like "King Kong" and "Faulad", and later as Hanuman in Ramanand Sagar's television serial 'Ramayan'. He was last seen in Imtiaz Ali's "Jab We Met" in 2007.