Believing his agency has been the victim of fraud, Ganus said, he has written to the public prosecutor’s office in Moscow to demand that it reopen the investigation.

“I believe in this report,” Ganus said. “When the investigation committee stopped the investigation, I disagreed with it.”

Details of the financial dealings at Rusada are merely the latest concern for the agency, and for the credibility of Russian sports.

Late last year, the World Antidoping Agency banned Russia from international sports for four years — including this summer’s Olympics in Tokyo — after finding that key laboratory data related to an earlier doping scandal had been manipulated. Russia has appealed its ban to the Court of Arbitration for Sport, which is expected to hear the case at the end of April or in early May.

The Baker Tilly analysis identified several companies that appeared to have only one customer, Rusada, and others in which a number of what it described as “former top managers” of the antidoping agency were investors or co-owners. The report also found examples of transactions with so-called “one-day” companies, which are operational for a short period of time, or for just a tiny number of transactions, before disappearing.

“We ask to pay attention to these purchases as a possible case of financial abuse by the key management of the organization,” the Baker Tilly report said. It warned that significant sums of money were spent on suppliers with “potentially high levels of risk and affiliation.”

Among the officials involved in the companies, the report said, was Ramil Khabriev, who resigned as the head of Rusada in December 2015. His departure came after WADA, the global doping regulator, suspended the agency for what it said was an industrial-scale doping operation involving Russian athletes.