Assailants on Saturday stabbed and seriously wounded Egypt's former anti-corruption chief who was also a top aide to a barred candidate for a March presidential election, his lawyer said.

Ali Taha said that Hisham Geneina was attacked by three men who "stabbed him in the face and beat him, breaking his legs," near his Cairo home. He was admitted to hospital for treatment.

Geneina was sacked by President Abdel Fattah al-Sisi as head of the Central Auditing Authority in 2016 after he was accused of exaggerating the cost of corruption.

On Saturday he was on his way to a court hearing to contest his dismissal.

A security source, speaking on condition of anonymity, confirmed Geneina had been wounded but said it happened during "a dispute with three young men following a car accident".

Geneina was top campaign aide to Sami Anan, a former armed forces chief of staff who this month announced he intended to stand against Sisi in the March election.

Anan's challenge was swiftly crushed, however, when the army accused him on Tuesday of forgery and other crimes linked to his registration as a candidate.

Sisi looks set to sweep to a second term after most of his serious challengers either ruled themselves out or were sentenced to time in prison.

Anan campaign team member, Hazem Hosny, said the attack on Genina was "politically motivated" -- a claim rejected by the security source.

Following the accusations made by the army, Anan was summoned by the military prosecutor and since then his family and lawyers have had no new of his whereabouts, Hosny said.

He is "the victim of a forced disappearance".

Geneina's lawyer said he had been barred from seeing his client in hospital.