LONDON, Dec 5 (Reuters) - Indian businessman Prateek Gupta asked a London judge on Tuesday to lift an order freezing his personal and business assets, alleging that commodity trader Trafigura failed to disclose full information when it sought the injunction.

In a court document, Trafigura rejected the allegations, saying that its demand was the product of meticulous investigation.

Below are the main issues in the court case.

LEGAL ACTIONS

Geneva-based Trafigura, a major industrial metals and oil trader, filed a lawsuit against Gupta in February, alleging that it had been victim of a $600-million fraud masterminded by Gupta and in which he and his companies participated.

Trafigura said it contracted with seven Gupta-owned companies to purchase nickel and paid for it, but the companies deliberately shipped much less valuable material.

Lawyers for Gupta in July rejected Trafigura's allegations.

In February, a London court imposed a $625 million global freezing order on bank accounts and other assets tied to Gupta and the companies, including those in Britain, Malaysia, Singapore and Switzerland.

That order is the subject of the court hearing on Tuesday.

The case comes against a background of a market struggling to fully recover from the crisis caused by a chaotic spike in nickel prices in March 2022. The case also prompted property and metals tycoons the Reuben brothers to seek $8.4 million in damages from Trafigura.

THE DEALS IN QUESTION

Trafigura entered into a series of nickel trading deals with Gupta's firms over several years. Most of the deals involved transit finance, in which Trafigura bought nickel from Gupta's companies and sold it back to them at a future date for a higher price.

This would earn Trafigura a return equivalent to the interest on the value of that nickel over the period the commodity trader owned the metal. Trafigura had the option of selling it on the open market.

For several years, Trafigura's deals with Gupta's firms were supported by finance from Citi, which has declined to comment on the case.

According to Trafigura, its relationship with Gupta's firms began to deteriorate during 2021-2022 as the need for bank financing rose and shipping time lengthened.

In October 2022, Citi withdrew its financial support for any new trades between Trafigura and Gupta's firms.

"On 9 November 2022, Trafigura inspected certain containers which were supposed to contain nickel. They did not," Trafigura said.

In June, Trafigura's metals division booked a $590 million impairment in its financial results in connection with the case.

GUPTA'S DEFENCE AND TRAFIGURA'S REACTION

In a court document released on Tuesday, Gupta alleged that employees at Trafigura worked with him to keep secret the deal to substitute nickel with scrap and other lower-value metal. He produced chat exchanges and emails with Trafigura staff that he alleges are proof that he was not alone in the deal.

Trafigura said in a separate document that Gupta's new evidence was vague and did not prove that its staff knew about the substitution.

It also said that Gupta's allegation did not disclose a properly arguable defence and was commercially preposterous.

Since Trafigura filed the lawsuit, some of the managers at the metals unit left the company, and Trafigura reshuffled its senior leadership positions, giving its energy trading unit more power at a senior level. (Reporting by Polina Devitt, additional reporting by Eric Onstad; Editing by Emelia Sithole-Matarise)