Tunisia's minister of culture has withdrawn a lawsuit filed against a cameraman due to stand trial on Thursday for filming an artist hurling an egg at the official, his lawyer said.

"The minister (Mehdi Mabrouk) withdrew his complaint against Mourad Meherzi, who was only doing his job," the minister's lawyer Mabrouk Kourchid told AFP.

He said the government official was ready to do the same for Nasreddine Shili, the filmmaker who threw the egg, if he apologised.

"The minister has no personal problem with this artist," the lawyer added.

Meherzi and Shili appeared in court on Thursday accused of conspiracy to assault a public official, as well as other charges including defamation. The charges carry a maximum of seven years in jail.

At the hearing, Shili also insisted on Meherzi's innocence, while the cameraman said he had just been doing his job.

"I confess to throwing an egg at the minister, but I swear it was a spontaneous act and that there was no complicity from Mourad," Shili said, adding that he had bought the egg on a whim, just a few minutes before hurling it at the minister.

The incident took place at a memorial ceremony on August 16 to mark 40 days since the death of a fellow artist, with Meherzi filming the attack and the images subsequently broadcast by Astrolab TV, for whom he was working.

The act was reportedly in protest at the inadequate response by the minister, an independent in the Islamist-led coalition government, to attacks on artists by extremists who deem their work offensive.

Meherzi was arrested two days later, while Shili was detained on August 21.

International rights groups had called for the charges against the cameraman to be dropped and accused the authorities of seeking to muzzle freedom of expression.

Tunisia's ruling coalition, headed by the moderate Islamist party Ennahda, is frequently accused by its critics of seeking to curb freedom of expression, a charge it strongly denies.