Barelli is standing against current President Julio Maglione at the FINA election due to take place during its Congress in Budapest on July 22. 

It is not precisely clear what he is challenging FINA over at CAS.

One case is thought to relate to FINA vice-president Dale Neuberger, a director of Lausanne-based TSE Consulting, who work for FINA. 

TSE also worked for Royal Dutch Swimming Federation President Erik van Heijningen before he lost by a 50-vote margin to Barelli in the vote for the LEN President last year. 

Neuberger has claimed he is not involved in TSE's work with FINA but is being challenged on the grounds of conflict of interest.

Other cases are believed to relate to Kuwait's FINA first vice-president Husain Al-Musallam.

CAS have still not confirmed any details of the hearing, but insidethegames understands that FINA will be represented by another vice-president, South Africa's International Olympic Committee (IOC) member Sam Ramsamy.

He will be present alongside legal advisor Jean-Pierre Morand from Carrard & Associés.

A row has also broken out between 63-year-old Barelli and African Swimming Federation (CANA) President Ramsamy following an insidethegames article last month highlighting comments from the former about the growing influence of Africa and Asia in FINA politics.

Barelli, a Roman Senator and former Olympic swimmer, suggested in a letter distributed among European Federation that Africa and Asia were attempting to gain control "not only of political power...but even more importantly, over the economic one also".

Ramsamy and several other African representatives have complained to Barelli and asked him to clarify and withdraw his comments.

FINA recently increased the number of Asian and African representatives on their ruling Bureau.

They also decided to abolish the position of honorary secretary, currently held by Barelli and traditionally a post for a European, and propose Ramsamy for the new spot of FINA second vice-president.

"The only comment I passed about Africa (and Asia) is, as you know, regarding the increments which have taken place in the past and which are foreseeable in the future, to the number of the FINA Bureau members from these two continents," Barelli wrote in a subsequent letter to Ramsamy and CANA members, also sent to insidethegames.

"May I remind you that, meanwhile, no change has been made or is foreseen for the other Continents (America, Europe and Oceania)."

He accused Ramsamy, a supporter of Maglione, of "manipulating" the contents of his letter and criticised his contribution to African aquatics.

"Rather than speculating on inexistent [sic] and false facts regarding a 'European letter' you would be better off addressing of the real problems you should be concerned with as CANA President," Barelli wrote.

"You have been a member of IOC and FINA for a long time. 

"Hence, why don't you ask yourself if you are really doing everything possible to ensure the development of aquatics within the African Continent.

"You are certainly aware that FINA has for some time achieved a very strong financial standing. 

"This has resulted from the attraction of strong sponsors who we thank for their support, the holding of successful events and the leading Federations who, with their exceptional athletes, guarantee the outstanding image of FINA.

"Have you ever proposed to FINA or demanded the allocation of financial contributions for the development of aquatic activities in Africa?"

Barelli added: "FINA needs to define clear criteria and give economic support to the developing Federations all around the globe. 

"There are many Federations in Africa, just as there are others in the other Continental Organisations that could benefit immensely from significant economic support. 

"This should have always been a top priority commitment for both you and FINA.

"Unfortunately, you have completely missed this opportunity."

Ramsamy claimed he is waiting for an "appropriate moment" to respond to Barelli's claims.

The 79-year-old has served as an IOC member since 1995 and has been CANA President since 2012.

He expressed his "deep disappointment" with Barelli's response to the concerns he raised about his Africa comments.

"You have utilised the response as part of your campaign to become the President of FINA at the forthcoming Congress in Budapest," Ramsamy wrote, in a letter seen by insidethegames.

"This is most disturbing and certainly deeply unbecoming of the Hon Secretary of FINA and President of LEN."

Maglione has promised to provide all FINA Member Federations with improved financial support but will wait until after his re-election in Budapest to do so to avoid it being seen as an electoral strategy.

The Uruguayan, 81, promised such support when speaking at the CANA General Assembly in Bloemfontein last October.

Maglione is still seen as the heavy favourite in the election due to the support he draws across Africa, Asia, Oceania and the Americas.

Barelli is hoping to increase his appeal beyond his European heartlands.

He is also the sole candidate for the European vice-presidential position, so is likely to remain involved in FINA regardless of his success in the Presidential election.