The head of Egypt's official corruption watchdog Hisham Geneina has requested the changing of the judge overseeing a probe against him over accusations of contempt of the judiciary and insulting a senior judge that date back to 2014.

The request by Geneina, the head of the Central Auditing Organisation (CAO), alleges a lack of impartiality on the part of judge Safaa El-Din Abaza after the latter had disclosed details about the investigations to the media, Geneina's lawyer Ali Taha told Ahram Online.

The case was brought by now- justice minister Ahmed El-Zend in November 2014 over a TV interview where Geneina spoke about corruption within the judiciary.

Geneina is also accused of slandering El-Zend.

The lawyer also said the judge could be bearing a grudge towards his client given that Geneina beat him in a 2002 election of the country's Judges Club.

Taha cited a statement by the judge – saying he would issue an arrest warrant against Geneina if he does not appear for questioning – as an instance of bias against his client.

Investigations were adjourned on Monday to 31 January to consider Geneina's request.

Taha also argued that under a law regulating the operation of the CAO, Geneina is at a minister's rank and should be subject to exceptional investigation measures in accordance with a1958 law.

Prosecutors are also separately probing recent controversial allegations by Geneina about he says is massive corruption within government institutions which led to the theft of LE600 billion over four years.

Geneina has repeatedly said that he uncovered the theft of billions of dollars since taking office in 2012, having issued reports involving some of the country's most powerful institutions, including the police, the judiciary and intelligence agencies.

A media gag order has been imposed by the prosecution in the corruption case.