The Indian billionaire Gautam Adani has fallen off the list of the world’s top 10 richest people as the value of shares in his companies continue to slide after an activist investor accused him of “pulling the largest con in corporate history”. Before the accusations published last week on Twitter, Adani, 60, was the world’s third-richest person with an estimated $119.5bn (£97bn) fortune. He has fallen to 11th place in the daily-updated Bloomberg billionaires index after a personal wealth wipeout of $34bn in just four days of trading since the accusations were published. Shares in Adani’s companies continued to slide on Tuesday despite a $400m investment from an Abu Dhabi investment fund linked to the country’s royal family. The value of Adani Group, his main conglomerate, has fallen by more than US$70bn since allegations of “brazen stock manipulation”, “accounting fraud” and “money laundering” were published by the short seller investment firm Hindenburg Research. Adani Group has denied the allegations, which it described as a “malicious combination of selective misinformation and stale, baseless and discredited allegations” and accused Hindenburg of attempting to damage its reputation before a large share offering. Shares in Adani Total Gas were down 10% on Tuesday, hitting a daily limit imposed by the Indian exchange designed to prevent rapid share price movements. Other related entities, such as Adani Green Energy, were also down in early trading in Mumbai. The investment from Abu Dhabi’s International Holding Company (IHC) comes as Adani tries to complete a US$2.5bn share sale, one of the largest fundraising campaigns conducted by an Indian company. The funding from IHC represents about 16% of Adani’s fundraising offer. IHC is the United Arab Emirates’ largest publicly traded company and is chaired by Sheikh Tahnoon bin Zayed al-Nahyan, a prominent member of the royal family. “Our interest in Adani Group is driven by our confidence and belief in the fundamentals of Adani Enterprises Ltd; we see a strong potential for growth from a long-term perspective and added value to our shareholders,” the chief executive of IHC, Syed Basar Shueb, said in a statement. IHC is the dominant company on Abu Dhabi’s stock market, and it has said it wants to boost global acquisitions, with a focus on food and clean energy. The wild trading was sparked by a report by Hindenburg that claimed the Adani empire was laden with debt and engaged in a “brazen stock manipulation and accounting fraud scheme”. Amid numerous allegations, Hindenburg cited a series of transactions tied to Adani’s Carmichael coalmine and rail operations in Queensland that it claimed may have allowed it to avoid disclosing to investors that some of the Australian assets had lost value – a charge the Indian conglomerate disputes. Hindenburg disclosed that it took a short position in Adani companies before it published its report. It is using financial instruments to profit from its falling share prices. A strong rally in the share prices of Adani companies could squeeze Hindenburg’s position. However, losses have continued to mount even after Adani published a 413-page rebuttal of Hindenburg claims early this week. The Indian conglomerate has described the Hindenburg report as a “calculated attack on India”, while the US investor said fraud could not be “obfuscated by nationalism”. Investors will focus on the results of the fundraising, due to end on Tuesday, which will affect how much debt Adani can pay down, as well as impact its expenditure plans. An unsuccessful share sale would heap even further pressure on the conglomerate, which requires a minimum subscription of 90% to proceed with the fundraising.