Billionaire Timchenko is the seventh-richest person in Russia with a net worth of $18.5 billion (£14.8 billion/€17.3 billion), with much of his wealth derived from oil and gas.

He has been a close ally of Russian President Vladimir Putin since the early 1990s, and is also chair of the Kontinental Hockey League Board of Directors.

Timchenko has been ROC vice-president since 2014, and was sanctioned by the United States in the same year in response to the annexation of Crimea from Ukraine.

He was among the oligarchs hit by further sanctions following the full-scale invasion of Ukraine last year, including asset freezes and a travel ban imposed by the Council of the EU.

Following the imposition of the sanctions, Timchenko stepped down from the Board of Directors of Novatek, Russia's largest natural gas producer, in March last year.

During the legal challenge against the EU's measures at the EU's General Court, Timchenko's lawyer Stéphane Bonifassi claimed ties to Putin did not make his client an ally with the Kremlin's policy on Ukraine.

However, the General Court rejected the argument the Council of the EU had insufficiently justified their sanctions.

"The Council gave reasons for the contested measures based on reasons that were sufficiently individual, specific and concrete to enable the applicant to defend himself, so that the complaint that the statement of reasons was inadequate or non-existent must be rejected," the Court's judgement said, as reported by Politico.

An appeal was also dismissed in a separate case brought against the Council of the EU by his wife Elena Timchenko.

The cases can be challenged at the Court of Justice of the EU's highest authority.

The war in Ukraine has led to uncertainty over Russia and its ally Belarus' participation at the Paris 2024 Olympics.

The International Olympic Committee controversially lifted an outright ban on both countries' athletes in March, recommending International Federations allow them to compete in international competitions as individual neutrals provided they do not support the war in Ukraine and are not affiliated to the military.

However, it says it has not taken a decision on their participation at the Games in the French capital.

Critics in Ukraine have argued there should be no place in sport for Russia or Belarus during the war.

In Russia, ROC President Stanislav Pozdnyakov, who last year encouraged athletes to fight in the war against Ukraine, has branded the IOC's conditions for its athletes to compete a "farce".