Three major UK bookmakers warned that tighter rules and higher taxes could push customers towards illegal gambling sites. At the same time, a supplier partly owned by them signed a revenue-sharing deal with an offshore casino network, according to an investigation published on October 1, 2026.

The contract linked Sports Information Services, known as SIS, to Santeda, a Curaçao-based casino network accused of targeting vulnerable gamblers in Great Britain without a Gambling Commission licence.

The arrangement emerged from the Casino Secrets leak, which exposed thousands of confidential files held by the Curaçao Gaming Authority, The Guardian reported.

The central question is not whether the bookmakers approved the deal. It is whether a supplier serving licensed operators carried out enough checks before doing business with an offshore gambling network.

What the leaked contract shows

According to The Guardian, SIS agreed in 2022 to provide Santeda websites with live sports content and betting data. The agreement covered two years and renewed automatically unless either party ended it.

The contract reportedly gave SIS a percentage of revenue from losing bets placed through Santeda brands. The amount SIS earned is not known. It is also unclear whether the agreement remains active. SIS declined to say whether it had been terminated.

SIS supplies horse racing, greyhound racing and esports content. Its data is used by gambling websites to settle bets.

The company is partly owned by Entain, which owns Ladbrokes and William Hill, and by Fred Done, the owner of Betfred. The Guardian reported that those three shareholders collectively own more than half of SIS.

Companies House filings examined by the newspaper suggest SIS shareholders received at least £37 million in dividends after the Santeda contract was signed. About £30 million was paid in 2023.

  • Entain owns about 23% of SIS through its Ladbrokes interests.
  • William Hill Organization held 19.5% of SIS at December 31, 2025.
  • Fred Done holds an estimated 8% stake, according to the investigation.

Why the arrangement matters in Britain

Great Britain requires commercial gambling businesses serving British consumers to hold an operating licence from the Gambling Commission. A licence from Curaçao or another overseas jurisdiction does not authorise gambling in Great Britain.

Advertising unlawful gambling can also be a criminal offence, according to Gambling Commission guidance. The distinction matters because an offshore licence does not create a legal route into the British market.

The Santeda network had previously been linked by investigative reporting to websites that appeared to target British customers, including people trying to stop gambling. The Guardian described those allegations as part of its earlier investigation. They do not amount, on their own, to a final Gambling Commission enforcement decision.

The leaked contract did not permit SIS data to be used in the UK. But The Guardian reported that it appeared to show SIS supplying information to several Santeda websites accused of targeting British consumers.

That creates a sharper governance question than a simple supplier relationship. The issue is whether a company serving licensed bookmakers should have carried out stronger checks before supplying a network operating outside Britain’s regulatory framework.

Bookmakers say they did not know

The companies are understood to have been unaware of the Santeda agreement when SIS signed it. Industry sources cited by The Guardian said controls designed to protect commercially sensitive information may have prevented Ladbrokes, William Hill and Fred Done from knowing about SIS’s dealings with a rival gambling business.

Entain said it was not involved in the commercial or customer arrangements SIS chooses to make. The company said it took the relationship seriously and had raised concerns with SIS.

SIS said its customers agree to offer its products only where doing so is legal and where the required licences exist. It also said it can suspend or terminate contracts when those conditions are breached.

A direct test of the black-market argument

The disclosure comes as licensed operators argue that higher taxes and tighter rules could drive British customers towards offshore websites.

Entain chief executive Stella David has warned that illegal operators could benefit from higher costs for licensed firms. Fred Done has made a similar argument over possible tax increases on gaming machines.

The SIS arrangement exposes the tension in that argument. Licensed bookmakers may be warning ministers about the risks of the black market while receiving dividends from a supplier that earned money from a network accused of serving that same market.

That does not prove that the shareholder companies approved the contract, knew about it or themselves supplied unlicensed gambling to British consumers.

It does show why the Gambling Commission identifies suppliers, payment firms, advertisers and technology providers as important points of intervention against illegal gambling. The regulator says licensed businesses should not be associated with, or supply services to, illegal gambling markets.

The unanswered questions are whether SIS ended the Santeda contract, how much money it generated and what checks the company now applies to offshore customers.

Until those points are clarified, the leak leaves Britain’s licensed gambling sector facing an uncomfortable contradiction: warnings about illegal competition carry less force when the same commercial ecosystem appears to profit from it.