An independent investigation into government and judicial corruption in the Turks and Caicos Islands, a Caribbean tax haven, has uncovered “additional serious matters,” according to the person leading the inquiry.

Helen Garlick, a former senior prosecutor at the U.K.’s Serious Fraud Office, was appointed to lead a criminal investigation after an earlier probe found evidence of systemic corruption in government and the legislature and among public officers.

Garlick said last week that her 30-strong team was making “good progress” but the costs of the investigation were putting a “major burden” on the islands’ budget, which relies on tourism and financial services.

“I have explained previously why this is an expensive investigation,” she said. “The Commission of Inquiry found indications of criminality on a huge scale and, since we have begun to investigate, we have discovered additional serious matters that must be examined.”

The offshore financial center is technically a British Overseas Territory, which means it comes under the legal jurisdiction of the U.K. But the British took direct rule of the islands last year after corruption allegations emerged.