The price of the large yellow diamond alternately shrank and spiked by about a million dollars as it moved across the globe.

The three-carat gem was shipped at least four times between shadowy companies allegedly controlled by Indian billionaire Nirav Modi over about five weeks in 2011, according to a report by a US bankruptcy examiner. The practice of round-tripping–trading a good repeatedly to give the appearance of distinct transactions–was central to the largest bank fraud in Indian history and ensuing criminal charges against celebrity jeweler Modi, according to the report filed August 25.

The rapid-fire sales were described as part of a plan in which Modi and associates “fraudulently borrowed approximately $4 billion over a period of years by manufacturing sham transactions purportedly to “import” diamonds and other gems into India using a web of more than 20 secretly controlled shell entities,” wrote John J Carney, the examiner in the bankruptcy case of three US jewelry companies indirectly owned by Modi.

The firms sought protection from creditors in February in New York as the celebrity jeweler’s empire unraveled. Authorities brought criminal charges against against him and alleged accomplices, and Modi became an international fugitive. He’s denied doing anything wrong.

The “fancy vivid yellow orange cushion cut” diamond was first sold by Firestar Diamond Inc, a US company indirectly owned by Modi, and shipped to Fancy Creations Company Ltd, a foreign shell company in Hong Kong also allegedly controlled by Modi, in August 2011, the report says. The price was almost $1.1 million.

The colorful stone was then shipped out two weeks later by Solar Export, a partnership formed by the Nirav Modi family trust, back to Firestar Diamond in the US, for closer to what it was really worth: $183,000, the examiner wrote.

Less than a week later, Firestar, which has offices on Fifth Avenue in New York City, shipped the diamond back to Fancy Creations in Hong Kong, this time for $1.16 million, the report asserts.

And two weeks after that, A. Jaffe, the New York City-based diamond company owned by Modi, sold the diamond to World Diamond Distribution, which the report describes as a Modi shell company in the United Arab Emirates, this time for more than $1.2 million.

The practice of round-tripping, which ultimately totaled $213.8 million between 2011 and 2017, the alleged duration of the fraud, generated shipping invoices that were given to the state-owned Punjab National Bank to obtain short-term loans using letters of undertaking, according to Carney.

The proceeds were then used to fund Modi’s lifestyle and business entities as well as using the funds from new loans to repay the old ones as they came due, the report states, citing a real-estate trust controlled by Modi that paid $25 million in cash for a luxury apartment in the Ritz Carlton on Central Park South in 2017.

Some of the shipments were so large and high-priced “that the packing slips alone should have raised suspicion,” wrote Carney, a former investigator and prosecutor for the US Securities and Exchange Commission and the Department of Justice. Carney was appointed in April to investigate links between the Modi-owned US companies and other Modi-controlled entities.