Opposition leaders on Thursday demanded an investigation by a Joint Parliamentary Committee or a Supreme Court-appointed panel into allegations by a United States investment firm that the Adani Group had committed large-scale corporate fraud.

Both Houses of Parliament were adjourned till 2 pm after the Opposition sought a discussion on the matter.

Last week, Hindenburg Research, a company that specialises in short-selling or betting against a company’s share price in the expectation that it will fall, alleged in a report that the Adani Group had engaged in decades of stock manipulation and accounting fraud. It also accused the conglomerate of improper use of offshore tax havens and raised concerns about high debt.

The conglomerate, led by Indian billionaire Gautam Adani, dismissed the report as a “calculated attack on India”. But shares in the billionaire’s conglomerate have plunged since the report and Adani lost his title as Asia’s richest person. Adani Enterprises, the conglomerate’s flagship firm, on Wednesday abruptly called off its Rs 20,000 crore follow-on public offering.

On Thursday, leaders of the Congress, Dravida Munnetra Kazhagam, Trinamool Congress, Aam Aadmi Party, Samajwadi Party, Janata Dal-United, Shiv Sena (Uddhav Balasaheb Thackeray) and the Kerala Congress attended a meeting in the Parliament complex before the session to chalk out a joint strategy.

“Keeping public interest in mind, we want a thorough probe into the Adani issue either by a Joint Parliamentary Committee or a Supreme Court-monitored committee,” Leader of Opposition in the Rajya Sabha and Congress president Mallikarjun Kharge told reporters later. “There should also be day-to-day reporting of the investigation on the issue.”

Aam Aadmi Party MP Sanjay Singh said that Adani’s “mountain of lies and fraud” is crumbling like a pack of cards. “Crores of investors in the country are worried,” Singh added.

He was referring to the high exposure of state-owned insurance company, the Life Insurance Corporation, to Adani Group companies. Over the past few years, LIC has heavily invested in the Adani group, channeling millions of rupees of middle class savings into the conglomerate. Any sharp fall in Adani stock prices will now end up affecting the returns of millions of LIC policyholders.

“The prime minister should come forward and address the issue,” Singh said. “The finance minister should tell what the RBI [Reserve Bank of India], ED [Enforcement Directorate] and CBI [Central Bureau of Investigation] are doing. Why is the government silent on such huge corruption?”