President Donald Trump speaks during a meeting in the Cabinet Room of the White House in Washington, D.C., Nov. 20. SAUL LOEB/AFP/Getty Images

The instance of President Donald Trump’s appearance in the Panama Papers – a trove of leaked documents, reveals in detail how the richest people in the world hide their unlawful business dealings from scrutiny.

A real estate deal from the early 1990s is the first instance of President Trump’s name being mentioned in the Panama Papers.

An investigative reporter, Jake Bernstein, Friday afternoon flagged the discovery that involves the purchase and subsequent sale of a unit at the newly constructed Trump Palace on the Upper East Side in the 1990s. This deal involved a Panamanian company named Process Consultants, Inc., that purchased a 16th floor condo at the Trump skyscraper in 1991.

Process Consultants was owned through bearer shares. These share certificates indicate that whoever physically possessed the papers owned the company. The bearer shares could be used to transfer assets completely anonymously and were favorite tools among money launderers.

Three year after the purchase in 1994, the Process Consultants decided to sell this condo at the Trump Palace. Trump Corporation was the exclusive broker for this. According to a contract document, which provided the details of an agreement, the apartment was sold for $395,000. However, later, the price appeared to have been cut down to $355,000. It is believed a woman from Hong Kong, whose name has appeared in other leaked documents had purchased the apartment, reported the New York daily News.

However, the New York City Department of Finance’s online database Automated City Registered Information System has information on the apartment only after 2005, which pointed out during this time the condo was owned by a Brazilian from Sao Paolo. He sold the unit for $795,400, that year.

Most of the Panama Papers do not specify the person behind Process Consultants and from where that person’s money came in. According to the New York Daily News, using bearer shares in no way meant that Process Consultants was caught up in dubious activities, though with the turnover it was believed to be money laundering.

The publication reported if Trump’s company knowingly facilitated the condo sale for the purpose of money laundering then the president himself could land in difficulty.

As part of his investigation into Russian election meddling, special prosecutor Robert Mueller had been looking into Trump’s sprawling real estate empire. It's unclear if the Process Consultants deal is of interest in the probe.

In 2015, Mossack Fonseca, a Panamanian law firm had leaked thousands of documents and Trump's condo contract was one among them. The Panamanian law firm sold unnamed shell companies across the world and had created more than 100,000 offshore entities by the year 2008. However, most Panama Papers do not indicate who is behind Process Consultants and their source of money.

The founders behind Mossack Fonseca were arrested after the massive leak. The firm is under investigation across the world.

Last month, the Paradise Papers leak revealed that Trump’s Commerce Secretary Wibur Ross had been involved in million dollar business deals with Russian President Vladimir Putin’s son-in-law, Kirill Shamalov.