Eugene Shvidler, whose net worth is estimated by Forbes magazine at $1.6 billion, became the "poster boy for Russian sanctions" when his two private jets were seized in March 2022, just after Russia's invasion of Ukraine, his lawyers argue.

The businessman was sanctioned that month by Britain's Foreign Office on the grounds of his association with Abramovich and his position as a non-executive director of London-listed Russian steel producer Evraz.

Britain also cites Shvidler's role at Russian oil company Sibneft, sold by Abramovich in 2005, as evidence he obtained a financial benefit from Abramovich.

But Shvidler - a dual British-U.S. citizen - argues that Britain was wrong to impose sanctions just because of his relationship with Abramovich, whom he describes as a close friend.

His lawyers say Shvidler did not receive any financial benefits from Abramovich, saying any payment he received from Evraz or Sibneft was from those companies and not Abramovich.

Shvidler's case will be closely watched as the first substantive challenge to British sanctions imposed following Russia's invasion.

Shvidler has no relationship with Russian President Vladimir Putin, no involvement in Russian politics and has not even been to Russia since 2007, his lawyer David Anderson told the High Court on Thursday.

The effect of British sanctions has been to "destroy his ability to deal with his assets and conduct his business, to disrupt his life and...to shatter his reputation", Anderson said in court filings.

However, Britain's Foreign Office argues his association with Abramovich - whom it says has benefitted financially from supporting Putin's government regime - justifies the sanctions.

Britain believes sanctioning Shvidler will "incentivise him to put pressure on Mr Abramovich to encourage President Putin to cease or limit" Russia's war in Ukraine, its lawyer James Eadie said in court filings.

Shvidler being sanctioned sends a signal to him and others that "there are negative consequences to having implicitly legitimised the government of Russia's actions", Eadie said.

(Reporting by Sam Tobin, Editing by Angus MacSwan)

By Sam Tobin