The son of a Russian oligarch locked in an acrimonious £453m divorce battle backed partly by Burford Capital called his mother’s agreement with the litigation funder “unlawful” when she dragged him into her case on Monday.

Tatiana Akhmedova, the ex-wife of oligarch Farkhad Akhmedov, accused 26-year-old Temur Akhmedov of helping his father evade a mammoth divorce settlement awarded to her four years ago and applied to add him to the opposing side of her case.

Ms Akhmedova and Farkhad Akhmedov — a former ally of Vladimir Putin — divorced in Russia in 2000 and she was later awarded the largest-ever divorce settlement in the UK. Ms Akhmedova enlisted Burford Capital to locate and chase her ex-husband’s assets around the world when he refused to pay, including a multimillion- pound mega-yacht, Luna, formerly owned by Chelsea football club owner Roman Abramovich.

In court filings presented on Monday, Ms Akhmedova accused British-born Temur Akhmedov, who was bought a flat in One Hyde Park allegedly by his father, of being given substantial sums by Farkhad Akhmedov in order to “put those assets beyond Tatiana’s reach”.

She is seeking to claim back money owed to her by potentially seizing her son’s assets and demanded to see documents detailing money given to him by his father, as well as information about the transfer of Farkhad Akhmedov’s assets to trusts in Lichtenstein.

Temur Akhmedov, now a commodities futures trader, slammed her arrangement with Burford Capital as “unlawful” in court documents presented on Monday morning, claiming family cases could not be funded by litigation finance and demanded the court give him access to documents detailing the arrangement.

Barrister Tim Owen QC, representing Temur Akhmedov, said there was a “real issue as to whether this type of arrangement is lawful in family proceedings where those are proceedings involving children or matrimonial property”.

Ms Akhmedova has rejected that claim, arguing there was no basis for her son to argue the funding was “illegal or contrary to public policy”.

In her own court filings, she argued “there is plainly a legitimate purpose in Burford Capital funding the international enforcement action required to unravel Farkhad’s (and Temur’s) schemes which would otherwise be prohibitively expensive”.

The bitter divorce row — which has been played out across jurisdictions including Dubai and London — has resulted in a public tussle over the oligarch’s assets, including a helicopter, private jet and the superyacht Luna.

The 380ft yacht, worth $490m, has become the trickiest piece of the puzzle. It was briefly impounded in Dubai in an apparent victory for Burford and Ms Akhmedova but was later ordered to be released by local courts last year. The vessel was subsequently reimpounded, according to Burford, and it remains the subject of bitter contest.

On Monday, the case was adjourned until March, when the court will resolve whether to add Temur Akhmedov to the case and whether to allow his request for disclosure.