But Verhaeren now says he is proud of the national team that has emerged from the 2012 "chaos" after making the tough decision to hand over the reins to Rohan Taylor for the Tokyo Games.

Working with the Dutch national team coaching his latest Olympic champion - sprinter Ranomi Kromowidjojo - at the 2012 Games, Verhaeren was oblivious to the drama unfolding in London for Australian swimming despite being on pool deck.

Even when the results of a damning independent review into Australia's 2012 campaign later made waves throughout world swimming, Verhaeren didn't really feel the motivation to read it.

It was only when Swimming Australia came knocking in late 2013 that Verhaeren felt compelled to scroll through the lengthy volume - and soon wished he hadn't.

The review launched after Australia won just one swimming gold in 2012 - their worst tally in an Olympic pool in 20 years - was a page turner, for all the wrong reasons.

It revealed a lack of team leadership and unacceptable athlete behaviour including bullying and the misuse of prescription drugs highlighted by the now infamous "Stilnox six" men's 4x100m freestyle relay squad.

"At the time I didn't realise at all what was going on in Australia," Verhaeren said.

"The review were published broadly and reached Europe but the reviews were so big that I didn't bother reading them - it was too much information.

"But when the question was asked to come (to Australia), I thought I would read into it to see what is going on.

"When I started reading ...I thought 'gee what am I getting myself into? What's going on here?"

It wasn't until he lobbed in Australia in January 2014 as the Dolphins first foreign head coach that he realised the extent of the challenge ahead.

"From the moment I came here in January 2014 I think a lot of work had been done to get some structure in the chaos," he said.

"From that moment on we have worked with very good teams.

"What I am incredibly proud of is the amount of trust we currently have in the organisation.

"When I arrived in 2014 that trust was either non-existent or pretty fragile.

"In 2012 and all the occurrences around the team and Swimming Australia had taken a massive toll amongst coaches, amongst the organisation."

Yet Verhaeren - who had also guided Dutch greats Pieter van den Hoogenband and Inge de Bruijn to multiple Olympic gold - soon applied his Midas touch to the Dolphins.

At the 2015 world titles Australia remarkably finished one gold shy of world No.1 United States.

At the 2016 Rio Olympics Australia had tripled their London tally with three gold including Kyle Chalmers claiming the country's first 100m freestyle title since 1968.

And they were well behaved - sometimes too well behaved.

"I have never experienced anything close to what I read about the team," Verhaeren said.

"I thought they were extremely well behaved, sometimes even too good if you ask me. I thought people might need to loosen up a bit."

The biggest highlight was to come at the 2019 world titles - an event that at first threatened to undo all of Verhaeren's good work.

Sprinter Shayna Jack had been sent home from a training camp before the titles even began before it emerged during competition she had failed a doping test.

In the meantime Australia's Rio 400m freestyle champion Mack Horton had been taking a stand against drug cheats, making global headlines when he refused to join China's controversial Sun Yang on the world titles podium.

It was enough to cause another "toxic" environment.

Yet Australia hung tight, winning five gold - including Ariarne Titmus' stunning 400m freestyle upset of distance queen Katie Ledecky - to place second overall and just eight medals behind the all conquering USA.

"What that world championships pointed out was that there is a team that could cope with pretty much every challenge that came along - and we had a few there," Verhaeren said.

"Keeping the team together, the organisation together and still having focus on performance - I think we can be proud of that."

It has convinced Verhaeren that he will leave Australia in safe hands with Leisel Jones' former coach Taylor after deciding to return to The Netherlands with his family in September, opting against staying on for the postponed 2021 Tokyo Games.

"The most important people are the ones leading within the team and that is actually happening at this point in time," Verhaeren said.

"That reassures me Australia is in a really good position for the years beyond to keep their focus on performance.

"I don't think there are any issues at all."

Australian Associated Press