PARIS: Iranian authorities released a young French academic who was accused of spying on bail on Sunday, the French presidency announced, after she spent six weeks in Tehran's notorious Evin jail.

University teaching assistant Clotilde Reiss, 24, was arrested in Tehran on July 1 after taking part in post-election street protests and was one of more than 100 defendants at a televised mass trial earlier this month.

She will now have to stay at the French embassy in Tehran while she awaits the verdict in her trial, which was heard on August 8.

Her father Remi Reiss said the young academic was "very happy" after being freed and seemed well.

"I thought she was on good form, she was very happy," he said after speaking with his daughter shortly after she was released.

"We are very happy. I spoke with Clotilde on the telephone. It is a big moment for us after an absence of a month-and-a-half," he went on.

Her family would now work towards getting her final and full release, the father added.

France has demanded that her case, and that against a Franco-Iranian embassy worker, be thrown out.

"The French authorities now demand that the judicial procedures levelled against Clotilde Reiss and Mrs Nazak Afshar -- which nothing can justify -- be ended as soon as possible," the French presidency said.

According to the statement, France's President Nicolas Sarkozy had spoken to Reiss by telephone and found her "in good health and good spirits", while he also thanked Iran's ally Syria for support in pushing for the release.

"He told (Reiss) of his joy and of the full support she enjoys from him and from all French people, who have followed her arrest and the trial to which she was submitted with concern," the statement said.

"He remarked on the dignity and the courage with which Clotilde Reiss has faced up to this test," the statement said.

"She turned 24 on July 30 in Evin prison, which is not an easy prison, which is an unbearable prison, to state things as they are," French Foreign Minister Bernard Kouchner had earlier told French state television.

Reiss was seized by Iranian authorities at Tehran airport as she tried to fly home after completing a six-month teaching and research assignment in the central city Esfahan.

In the closing weeks of her stay she witnessed some of the street protests that erupted after President Mahmoud Ahmadinejad's disputed re-election.

According to Kouchner, Iranian authorities accused her of spying after she took souvenir photographs of the marches and sent them to friends. State media in Iran have said she has also admitted sending a report to the French embassy.

France has firmly insisted that Reiss is innocent of any espionage and has demanded her unconditional release, but Iranian prosecutors have said that she must remain in Iran pending the verdict in her case.

"Judgement has not been given. Perhaps in eight days, perhaps after a little bit longer, the verdict will be given. In the meantime, she has to stay at the embassy if she is freed," Kouchner explained.

Reiss's family had been told that her release on bail was imminent and her father previously said that the French state was ready to pay bail of "several hundred thousand euros". Kouchner would not confirm the figure.

The French embassy employee, Franco-Iranian dual national Afshar, who was also among the 110 alleged protest supporters to have been rounded up for trial, was released on bail on Tuesday.

France had praised Syria, a former pariah which is in the process of mending strained ties with Paris and is Iran's closest ally, for helping negotiate Afshar's release, and did so again after Damascus helped free Reiss.

According to the statement, Sarkozy thanked "the countries of the European Union and other allies, such as Syria, for the support they have shown and will continue to show until our two compatriots regain their full liberty".LINK