Gyárfás, a former FINA vice-president and the head of the Hungarian Swimming Federation (MUSZ) from 1993 until 2016, was detained by police in connection with an investigation into the murder of media tycoon Janos Fenyo 20 years ago.

Fenyo, who owned a portfolio of newspapers and magazines and a television network, was gunned down while in his car in February 1998.

Slovakian Jozef Roháč was sentenced to life in jail for the killing of Fenyo, who Gyarfas apparently considered a rival, in May of last year.

It was not said then who ordered the murder, however, and Hungarian police decided to reopen the case last October.

Gyárfás has been placed under house arrest and must wear an ankle monitor so his movements can be tracked.

He has denied wrongdoing and has referred to the charges as "absurd".

MTI named Gyárfás as one of two men who were questioned and arrested as part of their ongoing investigation along with Tamas Portik, who was sentenced last year to 13 years in jail in an unrelated case.

Gyárfás has been a controversial figure in Hungarian swimming in recent years and resigned from his role at the helm of the MUSZ in 2016.

He stepped down from a position he had held since 1993 following pressure from athletes such as three-time Olympic champion and multiple World Championships gold medallist Katinka Hosszú, who called for him to quit.

A catalogue of problems were alleged by swimmers, including Hosszú and Hungary's International Olympic Committee Athletes' Commission member Daniel Gyurta.

Gyárfás was also a FINA vice-president until last year and remains on the organisation's Bureau and Executive Committee.

He is considered an ally of FINA President Julio Maglione and is also still the treasurer of European Aquatics (LEN).

"FINA is aware of the media reports regarding FINA Executive member, Tamas Gyárfás," FINA said in a statement to insidethegames.

"We will continue to monitor the situation closely as we await for further developments of the ongoing investigation."

LEN added: "In the wake of the media reports on the developing case related to LEN treasurer Tamas Gyárfás, LEN keeps monitoring the situation and waits for any development in the investigation."