A billion-pound row in which two oligarchs are wrestling for a stake in one of the world’s largest fishing businesses took another twist this week as lawyers for one of the men sought assurances over a mystery funder.

Russian businessman Alexander Tugushev is fighting billionaire Vitaly Orlov in the High Court for a stake in the $1.5bn (£1.2bn) Norebo Group. Orlov took control of Norebo in 2016 but Tugushev, who is being backed by a third party, claims his one-third stake in the company is not being recognised. An order against Orlov, freezing £270m of his assets, was granted earlier this year.

Lawyers for both men were in court today ahead of an expected two-day hearing next month. Orlov, represented by City firm Macfarlanes, is challenging the jurisdiction of the English courts and resisting the continuation of the freezing order.

In court today, Orlov’s lawyers requested either a security for costs order, or failing that, an order that Tugushev reveals who is funding his case.

According to a skeleton argument seen by the Gazette, the amount sought in security is £2.7m. That amount is 80% of the £3.3m overall estimated costs incurred by Orlov. 

The estimate is based on Orlov’s proposed costs for the upcoming applications and work done in preparation.

Appearing for Orlov, Christopher Pymont QC told the court the case was 'high value, hard fought litigation’ and that Orlov had been submitted to a ‘ferocious campaign’ by Tugushev.

Appearing for Tugushev, Helen Davies QC, instructed by Peters & Peters, said the £2.7m could not realistically be agreed to as there was not a detailed enough breakdown of costs, including what work was done and the seniority of the relevant fee earners.

Christopher Hancock QC, sitting as a judge in the High Court, said he would reserve judgment until next week.