The owner of a leading Dutch football club has funded it with loans from Roman Abramovich, leaked documents suggest, fuelling questions about the continued influence the Russian oligarch, under sanctions from the EU and UK, still has on football.

Details of the arrangement involving Valery Oyf, who took over ownership of Vitesse Arnhem in 2018, have been uncovered by the Guardian and the Bureau of Investigative Journalism (TBIJ).

The papers raise questions about whether Abramovich, the former owner of Chelsea FC, is still involved with a European club despite being subject to sanctions in the wake of Russia’s attack on Ukraine.

They have emerged three weeks after the Dutch football association (KNVB) deducted Vitesse 18 points for breaching its licensing regulations, officially confirming their relegation from the Eredivisie, the Netherlands’ top flight.

The KNVB started investigating Vitesse after reporting by the Guardian and TBIJ uncovered apparent financial ties between the club and Abramovich involving the club’s two previous owners. The KNVB said the club had been given a record sanction because of repeated breaches of licensing rules and withholding information.

It added that there were “indications” that Abramovich, the former owner of Chelsea had controlled, or still controlled, the club and that there are risks of violation of ­sanctions and money laundering.

The Dutch ministry of economic affairs and climate change is investigating whether there any links between Vitesse and Abramovich, in the light of EU sanctions imposed on him in 2022, as part of an international effort to target wealthy and powerful Kremlin allies in response to the invasion of Ukraine.

Further urgent questions have been raised by new documents suggesting that Abramovich was the source of almost all of the money, almost $200m (£160m), used by Oyf to fund an offshore company, ­Matteson Overseas Ltd.

The documents are part of the Cyprus Confidential files, shared by the International Consortium of Investigative Journalism and Paper Trail Media.

Other Abramovich associates are under sanction in the UK but not the EU.

Oyf, a long-time business associate of Abramovich and previously a senior figure at the Russian’s oil company, Sibneft, has previously denied claims that the oligarch still had ties to Vitesse.

However the paperwork sheds light on how Oyf ran Vitesse after his takeover in 2018. Oyf, who has so far been unsuccessful in his attempts to sell the club, owned Vitesse directly but Matteson Overseas Ltd was used to provide to them with funding and financial guarantees.

According to leaked documents seen by the Guardian and TBIJ, Matteson was almost entirely bankrolled by Abramovich. Abramovich’s companies granted Matteson tens of millions of dollars in loans, which were then invested in other entities linked to him and his asset management company, Millhouse Capital. Profits generated were used to pay off loan debt and fund further ventures, including Vitesse.

Over the course of a decade, Abramovich loaned nearly $200m to Matteson, which invested in various Millhouse-led ventures including listed companies such as Evraz and Highland Gold, mining concessions in Russia and large-scale securities lending. The documents stem from Meritservus, a Cyprus-based financial services company which administered much of Abramovich’s offshore network. The files show Meritservus also acted for several Oyf companies which were heavily linked to Abramovich.

Matteson has been based in the British crown dependency of Jersey since 2020 and it shares a nominee director with several of Abramovich’s companies. Oyf also acted as director for Abramovich’s company Greenleas International in early 2022, during which time he approved the sale of hundreds of millions of dollars of assets just weeks before sanctions were imposed on Abramovich. One of those deals included the sale of $61m shares in the Russian search engine Yandex to Oyf’s own company.

Abramovich was forced to end his 19-year ownership of Chelsea after the imposition of sanctions by the UK government, who oversaw the sale of the Premier League club to Todd Boehly and Clearlake Capital. But the revelations about his ties to Vitesse, who were once described as “Chelsea B” because of the close relationship between the teams, will raise questions for football’s authorities about the risks of multi-club ownership.

On the surface, it may seem that it was beneficial for a small club such as Vitesse to have a financial connection to Abramovich, whose wealth lifted Chelsea to unprecedented levels of success. Chelsea loaned a host of talented young players to the Eredivisie side during Abramovich’s time at Stamford Bridge. However, the revelations contained within the documents suggest that the Dutch side were vulnerable to punishment from the KNVB after Abramovich was placed under sanction by the EU.

It also appears that rules set by Uefa, European football’s governing body, on multi-club ownership were at risk of being broken by the arrangement between Oyf and Abramovich. The rules state that “no individual or legal entity may have control or influence over more than one club participating in a Uefa club competition”, which suggests a breach would have taken place had Vitesse ever been in the same competition as Chelsea before Abramovich ceded control of the Stamford Bridge club.

Oyf is not under sanction. He has previously denied claims that ­Abramovich still had ties to Vitesse. Oyf announced his intention to sell the club after the Russian invasion of Ukraine.

Vitesse have been left in deep financial trouble and were already bottom of the league before being hit with a punishment that left them at that point on -1 points. The KNVB’s licensing committee added that there was a risk that sanctions had been “violated”.

Vitesse said the deduction had been “inevitable”, citing factors including their submission of incorrect half-yearly financial figures and their inability to demonstrate that they did not have ties to Abramovich. They are at risk of their professional licence being revoked, with the possibility of bankruptcy looming over the club.

Last year, TBIJ and the Guardian found Abramovich had used a complex network of offshore companies to lend at least €117m (£100m) to Vitesse under its two previous owners, Merab Jordania and Alexander Chigirinsky, who are both known to be close to the oligarch. Oyf bought Vitesse from Chigirinsky.

The KNVB rejected a proposed takeover of the club by the American private equity outfit Common Group earlier this year, saying the company had not provided enough information about the ultimate source of its funds.

Responding to questions from the Guardian, a spokesperson for the KNVB said the change of ownership predated its “Know your owner” regulations. “The Dutch licensing committee of the KNVB launched a third investigation into Vitesse in 2023. The investigation was carried out by external parties/organisations. Based on the regulations of the ‘Know your owner’ principle, a transfer of (25%+ of) the shares requires the prior approval of the Dutch ­licensing committee.

The licensing committee expects from Vitesse that it shows that it acts in accordance with the applicable rules and regulations on the EU sanctions before any transfer of shares of Vitesse will be approved.”

Vitesse declined to comment. Oyf, Abramovich, Chelsea and representatives of Meritservus did not return requests for comment.