Russian billionaire Mikhail Fridman failed to win some relief from strict sanctions imposed on him, after a UK court denied his request for access to extra cash to pay for staff and the upkeep of his north London mansion.

The court agreed with the UK’s Office of Financial Sanctions Implementation, which had decided the additional payments requested for maintenance of the house were not for “basic needs” but enable Fridman “to continue enjoying the lifestyle he had prior to being designated.”

London courts have seen a flurry of challenges to the UK’s sanctions regime since the government imposed them on a number of Russian billionaires and businesses in the wake of the country’s invasion of Ukraine. Britain’s National Crime Agency dropped its investigation into alleged sanctions evasion by Fridman after a high profile raid of his home.

Fridman will continue the fight against the curbs “until all legal avenues have been exhausted,” he said in a statement, claiming that the sanctions regime undermines the presumption of innocence and is unjust. “This sends a disconcerting message to potential foreign investors in the UK: that property rights may no longer be as sacrosanct as once believed,” he said.

Fridman had sought permission to pay a £30,000 ($36,401) monthly management fee as well as payments for internal phone lines, TV equipment and staff costs.

“OFSI acted rationally and within the bounds of its residual discretion,” the judge said in the ruling published Thursday. The government had permitted the billionaire to make payments of around £1 million for ongoing already incurred expenses and cover Fridman’s “basic needs,” the lawyers for the government had said during the hearing.

Fridman bought his property, named Athlone House in London’s Highgate, for £65 million in 2016.

He is the founder and main shareholder of Alfa Group, which includes Russia’s largest private bank. The European Union and the UK imposed sanctions on Fridman and his partners soon after Russia invaded Ukraine in February 2022. The US sanctioned him in August, while he was living in London.

Fridman, who holds Israeli and Russian citizenship, left London earlier this month for Israel, complaining it was impossible to live in the UK under the sanctions regime. He moved to Israel and then flew to Moscow after the attack by Hamas militants on the country.

(Corrects timeline of Fridman’s movements in the last paragraph)