International Rowing Federation (FISA) President Jean-Christophe Rolland called for Tokyo 2020 to keep to its original plan after a warning that rowing events may be moved 400 kilometres outside of the Japanese capital.
The suggestions followed a report from the Tokyo Metropolitan Government Task Force, commissioned by new city Governor Yuriko Koike, which claimed last week that the budget for the Olympic and Paralympic Games would balloon to ¥3 trillion (£22 billion/$30 billion/€26 billion) unless drastic changes are made.
The report proposed rowing and canoe sprint competitions be shifted to Tome in Miyagi Prefecture, from its original planned venue at the Sea Forest International Regatta course on Tokyo Bay.
It followed concerns over renovation at the Sea Forest facility.
The sports world was largely taken by surprise by the report but is now deeply concerned at the proposed venue changes, as well as the supposed negative impact on the reputation of the Olympic Games.
At present, all of the Task Force recommendations are advisory, and no firm proposals have been made by Koike, who was elected into her role in July.
Rolland, an Olympic gold medallist at Sydney 2000, flew to Tokyo to take part in meetings with Koike to reportedly seek clarifications on the proposed plan.
International Olympic Committee (IOC) Coordination Commission chairman John Coates also participated in an emergency teleconference call with Tokyo 2020 chief executive Toshirō Mutō and the city's vice-governor, Takashi Yamamoto.
"I think it's a fantastic place for our sport, not only for the Olympic Games but I'm sure in terms of legacy for the future," Rolland said according to Japanese news agency Kyodo News following a visit to Tokyo Bay.
"I'm still convinced that this project is the best project."
The International Federations will have to agree to any changes, though they may privately still be frustrated if they do go ahead.
Japan Sports Agency Commissioner Daichi Suzuki insisted the alterations would need to be heavily studied and evaluated in order to avoid confusion.
"If we do not investigate how much [this change] would cost, it will lead to confusion," said Suzuki.
"If we do revise the plan, we need to know in what fashion it will be done."
IOC President Thomas Bach said they would discuss the report, which predicted a four-times increase of the Tokyo 2020 budget, in a "constructive way" with organisers.
Bach, speaking on a visit to 2024 Olympic and Paralympic Games candidate Paris, asserted that the rising costs could be as a result of the high price of construction in the Japanese capital city.