The disclosure comes in WADA’s recently published 2019 annual report.

Pointing to a "significant" increase in project consulting fees, the summary of the agency’s financial performance contributed by Dao Chung, chief financial officer, attributed this in particular to "the independent investigation and ensuing report into allegations of improper conduct by Executive Committee members raised by two Chairs of Standing Committees."

It went on: "This particular case alone represented 45 per cent of the total year-over-year increase of $3.5 million (£2.7 million/€2.9 million) in the overall financial statement compared to 2018."

Forty-five per cent of $3.5 million amounts to $1.575 million (£1.2 million/€1.32 million).

The investigation, by law firm Covington and Burling LLP, arose from allegations of improper conduct made by Beckie Scott and Edwin Moses, both Olympic gold medallists as well as WADA Standing Committee chairs, against Francesco Ricci Bitti and the late Patrick Baumann.

The firm’s 133-page report concluded that no one at an Executive Committee meeting in September 2018 "bullied or harassed Ms Scott" regarding her objection to the controversial reinstatement of the Russian Anti-Doping Agency (RUSADA).

It said that the "exchange between Ms Scott and Messrs Ricci Bitti and Baumann at that meeting took place after Ms Scott presented the Athlete Committee report.

"While Mr Ricci Bitti’s response to that report reasonably could be viewed as aggressive or disrespectful, his behaviour did not rise to the level of bullying or harassment."

Moreover, "while Mr Baumann objected to Dr Moses having spoken on a particular issue at the May 2018 Executive Committee meeting", the investigation "uncovered no credible evidence that Dr Moses was told to 'shut up' at that meeting or the Foundation Board meeting held the next day."

Both Scott, the first North American woman to win an Olympic medal for cross-country skiing, and Moses, the dominant 400m hurdler of his day, declined to participate in the investigation after claiming the process was "fatally flawed."

They subsequently expressed "extreme disappointment" at the outcome.

The report made four recommendations to address "ongoing tension over allocation of power among different WADA constituencies" and other issues.

In spite of the cost of the investigation, WADA recorded a small surplus for 2019, with income of just over $38 million (£28.9 million/€31.5 million), excluding financial income, all but matched by $37.8 million (£28.7 million/€31.4 million) of operating expenses.

Broadly, 50 per cent of the agency’s income is derived from the sports movement and 50 per cent from Governments around the world.