The 47-year-old Dutchman took over as head coach in 2013, a year after Australia recorded their worst Olympic medal haul in the pool for 20 years at London 2012.

Under his stewardship during Rio 2016, Australia came second behind the United States in the swimming medal table, winning three golds, four silvers and three bronzes.

Verhaeren extended his contract until Tokyo 2020 in December 2015.

In an interview with The Australian newspaper, the Dutchman claimed that there is a lack of "true leadership" within the world governing body and their failure to adopt a tough policy on anti-doping left him frustrated.

"At the last coaches meeting, at the World Short Course Championships in December, I challenged FINA to produce a strong statement for clean sport after what had happened in Rio with allowing Russia back in," Verhaeren told The Australian.

"As a world federation you need to step up in leadership, but I haven’t seen any of that from FINA.

"They keep talking about how much drug-testing they are doing but that’s not the problem.

"It is the lack of a statement and vision and true leadership to say this is what we stand for.

"There is a lack of courage."

Following the second part of the McLaren Report, which found 1,000 Russian athletes had doping samples manipulated and tampered with between 2011 and 2015, the International Olympic Committee ignored pressure from the World Anti-Doping Agency and elsewhere to introduce a blanket Russian ban at Rio 2016 and permitted International Federations to adopt their own eligibility criteria, which were applied with differing levels of severity.

Russia's swimming team's participation at Rio 2016 was overshadowed by doping allegations.

Seven members of the country’s 37-strong squad, including breaststroke star Yuliya Efimova, were declared ineligible by FINA following the publication of the McLaren Report, only to be granted permission to compete just days before competition began following successful appeals to the Court of Arbitration for Sport.

Efimova claimed silver medals in both the women's 100 metres and 200m events and Anton Chupkov and Evgeny Rylov won bronzes in the respective men's 200m breaststroke and men's 200m backstroke finals.

"When the second part of the McLaren Report came out in December, that was deeply concerning with the number of athletes mentioned there," said Verhaeren.

"But the feedback from FINA was that they were happy because there was no mention of swimming.

"There’s no doubt that in those hundreds of athletes there are swimmers involved as well.

"FINA’s response does not reflect the concern of the community of swimming.

"I do believe that overall swimming is a clean sport but it doesn’t mean we are not in danger of having the same problems as other sports in some countries and with some individuals.

"But FINA will not stand up for clean sport and condemn doping and speak to our deepest concerns about the McLaren Report."

FINA President Julio Maglione was forced to hit back at criticism from three resigning members of the organisation's Doping Review Control Board (DCRB) in September after they claimed calls for stricter punishments were overlooked.

Canada's DCRB chair Andrew Pipe announced his resignation in a letter addressed to Maglione also signed by Susan White, the former chief medical officer for Swimming Australia, and Larry Bowers, the chief science officer of the United States Anti-Doping Agency. 

The trio claimed that unanimous recommendations of the DCRB to adopt strict criteria regarding Russian eligibility at Rio 2016 were ignored in favour of more lenient measures.

The trio then claimed they were not made aware of who had ultimately been permitted to compete at Rio 2016 by the FINA Bureau until they saw them swimming during the Olympic competition.