TONY EASTLEY: In Egypt a former heart surgeon who's now a political satirist has been detained by police for questioning over claims that he insulted Egypt's president.

Bassem Youssef has an audience estimated at around 30 million and his pithy take on politics, often skewering the nation's new Islamist rulers, has rubbed plenty of people up the wrong way.

Middle East correspondent Matt Brown reports.

(Crowd cheers)

MATT BROWN: As Egypt goes through a violent and prolonged transition, Bassem Youssef is to many the man of the hour.

His fans love his irreverent style, delivered with witty one-liners and corny screen graphics, targeting the political elite.

BASSEM YOUSSEF: They actually have to live with the fact that they are coming in as an employee, not as a pharaoh, not as a king and they actually have to live with people making fun.

MATT BROWN: In the lead-up to Egypt's presidential elections, Bassem Youssef was relishing the end of Hosni Mubarak's authoritarian rule.

INTERVIEWER: Who would you like to see running Egypt going forward?

BASSEM YOUSSEF: I don't know, I'm between like choosing the best person and the best person to make fun of.

MATT BROWN: Elections delivered power to the Islamist president, Mohammed Mursi and his supporters in the Muslim Brotherhood, which now dominates Egypt's parliament. And more often than not they are Bassem Youssef's targets.

(Bassem Youssef speaking, audience laughter)

Bassem Youssef swings between high-brow satire and low-brow physical spoof. He's lampooned Islamist assassins and opened his show with a silly oversized hat in the style of one worn by Mohammed Mursi on a state visit.

But the jester is facing a moment of truth - for himself and Egypt.

(Drumming and chanting)

Last week the chief prosecutor, appointed by Mohammed Mursi, issued an arrest warrant accusing Bassem Youssef of insulting the president.

It's not the first time Islamists have complained about his humour, and all along he's distinguished between his Islamic faith and his Islamist targets.

BASSEM YOUSSEF: Our battle is not with religion but with the people who misuse and abuse religion for their own political agendas.

MATT BROWN: Yesterday he remained defiant. Surrounded by an unruly crowd of supporters, Bassem Youssef presented himself to the authorities at Egypt's High Court. For a while he even donned that oversized hat. Then he disappeared inside for questioning.

On Twitter he found time to made fun of the proceedings. But this case is feeding into concern about the way Egypt's new rulers are dealing with their detractors and the way those detractors are taking their case to the streets.

After riots targeted Muslim Brotherhood offices a week ago, prosecutors issued warrants to arrest five prominent pro-democracy activists. President Mursi warned he was close to taking emergency action to protect the nation, accusing the opposition of using the media to incite violence, and a senior aide pointed to the need to distinguish "freedom of expression and thuggery".

Bassem Youssef was freed after five hours on $2,200 bail and his next show will be keenly watched.

Rights groups warn freedom of expression has been under sustained attack in Egypt, but with elections delayed by a court challenge, it's going to be a long and rowdy year.

This is Matt Brown reporting for AM.