Tom Watson, MP for West Bromwich East, told the BBC Asian network channel, that he has seen "top secret papers from Mrs Thatcher authorizing SAS (Special Air Services) to collude with the Indian government."
According to the MP, UK government is trying to hold back some documents about the operation. It must disclose more information, he said. "This trying to hide what we did...not coming clean...would be a very great error," he said.
"I am writing to the Foreign Secretary about this matter and will raise it in the House of Commons. I expect a full explanation," the MP said on his website.
Operation Blue Star, which was hailed as a success, earned Indira the wrath of the Sikh community. She was later murdered by her Sikh bodyguards. More than 1,000 people were killed in the operation.