A major North Sea shipping firm has broken ties with its oligarch owner – but questions remain over the true extent of its links to Moscow.

Aberdeen-based OEG Group said it was “no longer related” to billionaire Vagit Alekperov, who is a key ally of the Kremlin, and added that it was “fully compliant” with international sanctions.

But the company is now controlled by former executives at the oligarch’s energy company, Lukoil.

A former Soviet government oil and gas minister, Alekperov was one of the business leaders summoned to the Kremlin at the end of last month as Vladimir Putin prepared for his invasion of Ukraine.

The 71-year-old Azerbaijani-born oligarch was ranked as the fourth richest man in Russia by Forbes magazine last year. He has so far avoided formal sanctions, but is on a US Treasury list of oligarchs close to Putin.

Last week, Alekperov sailed his superyacht from Spain to Montenegro, where he can avoid an EU crackdown. Now he has cut ties with OEG Group – one of the world’s biggest providers of specialist containers used in offshore developments.

The UK-registered company used to be largely owned by a Cypriot firm called Morcell Limited, which is linked to Alekperov. But OEG this week told openDemocracy it is no longer owned by Morcell.

On March 3, the firm made filings to the UK’s corporate registry, Companies House, declaring three new persons of significant control (PSCs). All were British citizens resident in the tax haven of Monaco.

Two of them – Pavel Novoselov and Pavel Sukhoruchkin – are, according to Forbes, former executives at Lukoil, where Alekperov is president and CEO.

OEG has a substantial Scottish North Sea operation, through its Aberdeenshire-based subsidiary OEG Offshore Limited.

In a statement, the company explained its ownership structure had changed. “Morcell Limited is not a shareholder in OEG Group Limited, or the wider OEG Offshore,” it said.

“As such OEG Group Limited, and the wider OEG Offshore group, are no longer related to Mr Alekperov, or Morcell Limited.”

The statement said: “We also wish to clarify that neither Mr Alekperov, nor Morcell Limited, are the subject of any UK or international sanctions, and nor were they during their period of ownership of OEG Offshore. [...]

“OEG Offshore is appalled by the current situation in Ukraine, and as such is fully compliant with all existing international sanctions. We have additionally taken pre-emptive action to halt any future business with Russia, in line with recent calls from the Scottish government.”

Alekperov is believed to have lost billions since Putin invaded Ukraine, as Lukoil is hit by uncertainty in the oil and gas market. The energy giant broke ranks last week by calling for an “immediate cessation of the armed conflict” in Ukraine.

The company, which has thousands of petrol stations, expressed “concern over the ongoing tragic events in Ukraine and its deepest sympathy to all those affected by this tragedy”.