Minister of External Affairs Sushma Swaraj hit back at the Congress in Parliament on Wednesday by stating that the then prime minister Rajiv Gandhi had allowed safe passage to the key accused in Bhopal gas tragedy case--Warren Anderson--in exchange for the release of his childhood friend, who was serving a 35-year sentence in the US.

Taking a jibe at Congress vice-president Rahul Gandhi, Swaraj, according to a DNA report, asked him to question his mother Sonia Gandhi, "Mumma, mumma, how my father released murderer of 15,000 people."

Warren Anderson was the chairman of Union Carbide Corporation when thousands of people were killed in a lethal gas leak accident at the pesticide plant of Union Carbide India Limited (UCIL) in Bhopal in 1984. Anderson, who died last year, was wanted in the Bhopal gas tragedy case, but he never faced any trial.

Referring to the autobiography of late Congress leader Arjun Singh, Swaraj claimed in the Lok Sabha that Rajiv Gandhi allowed Anderson to escape from India in exchange for the release of his childhood friend Adil Shahryar--the son of Muhammad Yunus, who was a close family friend of the Gandhis and also a former ambassador to Spain, Indonesia and Turkey.

Shahryar was arrested in August 1981 and was serving a 35-year sentence in a US prison for setting ablaze his room at Sheraton Beach Hotel and for a fraud and other violations in Florida, according to reports.

In the book, Singh had written that Rajiv Gandhi had ordered him to make arrangements for the safe return of Anderson to the US, Swaraj said.

Anderson was under a house arrest after he was detained by the Madhya Pradesh police soon after he arrived in Bhopal on 7 December, 1984. However, he was released after Singh, the then chief minister of Madhya Pradesh, received a call from Delhi. He was then immediately flown to New Delhi on a state government's plane and sent to the US on the same day.

According to a report published in The New York Times on 15 August, 1985, Shahryar was granted clemency by President Ronald Reagan on 11 June, 1985, the same day Rajiv landed in the US, ABP Live reports. However, Rajiv had denied the allegations.

"Unlike other Presidential papers, grants of clemency are not routinely published by the White House and made available to the press, accounting for the action's lack of notice. The Shahryar commutation was reported in the Indian press and confirmed by the White House press office, which referred a caller to the Justice Department for comment," the article says.

On 2 December, 1984, leakage of methyl isocyanate gas at the pesticide plant resulted in the death of thousands of people and affected more than 50,000.