Amitabh Bachchan, the Bollywood superstar, has revealed that he is suffering from cirrhosis of the liver after contracting hepatitis from a blood transfusion.

Bachchan, known as the “Big B” and voted the greatest actor of the millennium in 1999 in a BBC poll, spent months critically ill in hospital after he ruptured his spleen while shooting a fight scene for the film Coolie in 1982. Thousands of fans held vigils outside his hospital and made offerings at temples as they prayed for his recovery.

On Friday the actor, 67, wrote on his blog: “200 [fans] gave blood. And 60 bottles of it was required and collected and injected into me … some of the blood from an unknown donor was infected.”

He added that 25 per cent of his liver had been destroyed.

The news shocked his millions of admirers again.

In 2005, suffering from intestinal infection, he was again admitted to hospital in Mumbai. Again India held its breath while dozens of television crews kept a 24-hour vigil and scores of fans prayed outside.

Two men walked hundreds of miles to Mumbai with water drawn from the holy Ganges river, which is said to have healing properties. Dozens of others performed acts of penance in the hope of speeding his recovery.

Yesterday Bachchan sought to calm distraught fans. “I am alarmed that you are alarmed at my condition,” he wrote on his blog. “It has been something that has remained with me for years and years and years.”

He added that he was aware that any disclosure about his health sparked widespread concern across India.

“Now since the liver and any ailment associated with it is extremely sensitive, I have to be under constant vigil and monitoring,” he wrote.

He added that cirrhosis was only one small part of his health issues.

“Some of them are at an extreme stage of repair and I may have to go under the knife sooner rather than later,” he wrote.