A massive leak of millions of documents from the Panama law firm Mossack Fonseca has revealed that 500 Indians, including prominent Bollywood actors, politicians and industrialists, had offshore holdings in tax havens across the world.

The list includes the names of actress and former Miss World Aishwarya Rai Bachchan, as well as her family members, and her father-in-law, Bollywood superstar Amitabh Bachchan.

Businessmen such as DLF owner KP Singh and his family members, Indiabulls chairman Sameer Gehlaut, Apollo Tyres chairman Onkar Kanwar and Vinod Adani of the Adani group also figure on the list. It also includes Mumbai gang-lord Iqbal Mirchi, industrialist Anil Salgaocar and lawyer Harish Salve.

According to investigations by the Indian Express, Bachchan was the director of four shipping firms in BVL and the Bahamas in 1993, which traded in millions of dollars. Rai, along with her brother, father and mother, were the directors of a firm in the British Virgin Islands in 2005, with the company being dissolved in 2008.

According to the Reserve Bank of India's rules, Indian citizens were not allowed to float overseas entities before 2003-04. In 2004, individuals were allowed to buy shares and remit funds up to $25,000 annually under the Liberalised Remittance Scheme, but barred from setting up companies abroad. This rule was changed only in 2013, when RBI permitted individuals to invest in joint ventures or subsidiaries under the Overseas Direct Investment window. The annual limit was also increased to $250,000.

The list of Indians was published by The Indian Express newspaper, which is part of the International Consortium of Investigative Journalism. The report stated that these companies were mostly set up before the rules were changed.

Black money is a major election issue in India. After the news broke, India's finance minister Arun Jaitley said that Prime Minister Narendra Modi had asked for the issue to be investigation. The government will form a multi-agency group to monitor the disclosures. "All unlawful financial holdings abroad will face action," Jaitley said.

The country's Supreme Court had already appointed a Special Investigation Team to look into black money. The team has asked government agencies to verify the leaks and prepare a report on the allegations.