Fifa has issued a strong rebuttal of claims by a Swiss special prosecutor that its president Gianni Infantino should face a criminal investigation over his use of a private jet in 2017.

The governing body called the statement issued by Stefan Keller “malicious and defamatory” and born out of “extreme bias”.

Keller said his enquiries had found that there were “clear signs of criminally reprehensible behaviour” in relation to the flight from Suriname to Geneva.

FIFA responded: ‘FIFA and the FIFA president are shocked by the statement issued today by ‘special prosecutor’ Stefan Keller.

‘The statement is both malicious and defamatory in nature and demonstrates his extreme bias.

‘Neither FIFA nor its president have ever been informed of these spurious new allegations and they are therefore unable to comment on them, which is probably the intention of the ‘special prosecutor’.’

The statement added that Keller’s method of publishing media releases “borders on character assassination and is rejected in the strongest possible terms by FIFA and its president”.

A press statement on Keller’s website said he had passed the case on to the Swiss federal prosecutor’s office.

FIFA’s ethics committee said in August that it was closing its investigation into the matter due to ‘the evident lack of a prima facie case regarding any alleged breach of the FIFA code of ethics’.

Keller passed the case concerning the flight on because his mandate is to look at meetings between Infantino and Switzerland’s former attorney general Michael Lauber.

Criminal proceedings were opened against Infantino in relation to those meetings on July 30 of this year after Keller concluded there were ‘indications of criminal conduct’.

Infantino and FIFA dismissed any suggestion of wrongdoing in relation to his meetings with Lauber, saying he had met prosecutors all around the world in relation to ongoing criminal cases in which FIFA was assigned victim status in regard to alleged corrupt activity at the world governing body prior to his election as president in 2016.

Speaking in early August, FIFA’s deputy general secretary Alasdair Bell said: ‘There is something a little bit grotesque and unfair about all this because we are 100 per cent confident that there will never be a criminal charge, far less a criminal conviction against the FIFA president.

‘But we have a situation, and we have to acknowledge this, where objectively there is damage to both FIFA and to the FIFA president simply because of the existence of this criminal investigation and we think that’s not right.’

FIFA added that it would “take all necessary legal steps and remedies to put an end to these baseless and ill-intentioned accusations”.