In an interview with Brazilian newspaper Estado, Dias claimed it is unfair what is happening.

“I feel harmed competing with athletes who are not new to the Paralympic Movement, on the contrary they are champions of the S6 class,” he said.

“Change was necessary, but not in the way it is being implemented.

“We hope that the responsible bodies will make things fairer and clearer.”

Despite his concerns, Dias has already secured one gold medal in London after winning yesterday’s 50m freestyle event in an Americas record time of 31.83sec, beating Bocciardo to top honours by a margin of 1.06 seconds.

The 31-year-old will also compete in the 50m backstroke, 50m butterfly and 100m freestyle, and although he has to swim with athletes who have greater mobility, he remains optimistic.

“The expectation is good,” Dias said.

“It is always a joy to be able to represent our country in an international competition, especially in a World Cup.

“We train a lot to get here and do our best.”

More than 650 swimmers from 81 countries are due to compete at the World Para Swimming Championships, a flagship competition en-route to the Tokyo 2020 Paralympic Games.

It is the second time in four years Britain has held the event, following Glasgow in 2015.

Competition runs until Sunday (September 15), after which Conrado anticipates further discussions on classification.

The IPC is currently led by a Brazilian President, Andrew Parsons.

When contacted by insidethegames regarding Conrado’s comments, an IPC spokesman said: “The changes we introduced in 2018 was a standardised testing methodology across all physical impairment classes and came as a result of a request from member nations and a wide-ranging consultation in the preceding years.

“Many of the changes are the result of membership feedback and follow collective input from international classifiers and sport-technical experts, as well as extensive testing in different nations.

“Throughout the entire process member nations have been kept informed at regular stages of the progress made.

“When presenting these changes and timeline in greater detail at the 2017 World Para Swimming Sport Forum in Mexico, the member countries provided positive feedback to World Para Swimming on the proposed changes and timeline for introduction.

“To use the VAR analogy, this is like a football manager calling for the introduction of VAR technology but then complaining about it when their team lose a goal because of it.

“We acknowledge that such changes have had an impact on several athletes who have either changed class or being found ineligible.

“More efforts need to be made by World Para Swimming and member nations to mitigate the impact such decisions have on an athlete’s well-being going forward and this has been subject to much discussion within the Paralympic Movement.”

Daniel Etchells | Inside the Games