Bollywood superstar Sanjay Dutt is "heartbroken" after judges upheld his conviction relating to the 1993 terrorist bombings in India and ordered him to return to prison.

The actor was sentenced to six years behind bars in 2007 for purchasing weapons from bombers who attacked Mumbai with a series of blasts, claiming 257 lives and wounding 713 others, and he spent 18 months in jail before appealing his punishment.

He was released on bail while he fought the case, but judges upheld the ruling and merely reduced his term to five years at India's Supreme Court on Thursday (21Mar13).

In a statement, a disappointed Dutt writes, "I am heartbroken because today along with me, my three children and my wife and my family will undergo the punishment. I know in my heart that I have always been a good human being, respected the system and always been loyal to my country."

The 53 year old, who alleged he needed the weapons to defend his family during widespread riots in 1993, was convicted of holding illegal arms in the run-up to the explosions across Mumbai.

He must surrender to authorities in four weeks' time to begin his sentence.