Investors in the former Russian oil company Yukos are confident they will receive a multi-billion pound financial settlement on Monday in a landmark case that threatens maximum embarrassment for BP and the Kremlin at a sensitive time.

Europe's top arbitration court in The Hague has been hearing a case about the illegal expropriation of assets brought by five investors including the former Yukos chief executive, Platon Lebedev.

A ruling in favour of GML, the majority shareholders in Yukos, would be damaging to BP because the disputed Yukos assets ended up in the hands of another major oil company, Rosneft, in which it owns a 20% stake.

It would also be a setback for the Kremlin at a time when it is under pressure from the west over its role in eastern Ukraine.

The claim, under the energy charter treaty, amounts to $103.5bn (£61bn), but the court will decide how much compensation GML should receive if the ruling goes in its favour. In the event of GML succeeding, Russia's response will be widely watched.

Yukos was originally set up by Mikhail Khodorkovsky with Lebedev's help, but the company crumbled in 2004 when the Russian government demanded it paid $27bn in taxes.

Both Khodorkovsky and Lebedev were jailed. They have recently been released, but Yukos's oil fields and other assets were auctioned off and eventually bought by Rosneft.

Yukos, once Russia's biggest company, and many western supporters maintained that the tax bill and jailings were a result of Vladimir Putin wanting to rid himself of oligarchs who were using their corporate power base to meddle in politics.

But the Kremlin has always argued that all the actions taken against Yukos and its executives were entirely justified under Russian law.

Khodorkovsky sold off his interest in Yukos to pay his legal expenses, but Lebedev and GML have brought what is believed to be the largest ever arbitration case in history.

The litigation was first filed in February 2005 but it took until 2009 before a ruling about the jurisdiction and admissibility of the claim was made in GML's favour.

Tim Osborne, a British lawyer and director of GML, is planning to make a statement about the arbitration findings when the court in The Hague makes its final ruling at 9am London time. The result is not yet known, but industry sources said: "They are organising a big press conference. They would not be doing this unless they expected to win."