TEHRAN - An Iranian prosecutor said on Monday a French teaching assistant charged with spying was freed on bail of about $300,000, media reported on Monday.

French President Nicolas Sarkozy's office said in a statement on Sunday that Iran had released Clotilde Reiss on bail but it did not reveal the amount. She is staying in the French Embassy in Tehran pending a verdict.

Tehran prosecutor Saeed Mortazavi confirmed the news about the 24-year-old and said the investigation had been concluded.

Clotilde Reiss was freed with the depositing of 300 million tomans (about $300,000) and the investigation about her has come to a conclusion, the semi-official Mehr News Agency quoted him as saying, giving no further detail.

Fars News Agency also carried his comments.

Sunday's statement by Sarkozy's office said Reiss was well and would stay in the French embassy.

Reiss has been charged in a mass trial with aiding a Western plot against the government after Iran's disputed presidential election in June and has been held in prison since early July.

A French embassy employee, Nazak Afshar, who faces the same charges, was conditionally released earlier this week by Iran and will also stay at the embassy ahead of the verdict.

Sarkozy thanked other countries, including Syria, for supporting France in the case, which has further strained already tense relations with Iran.

Earlier on Sunday, French Foreign Minister Bernard Kouchner told state television that France had agreed to post bail for Reiss, saying the authorities had not sought an enormous sum.

The verdict might come in the next eight days. Perhaps a bit longer, he said.

(Reporting by Hossein Jaseb and Hashem Kalantari; writing by Fredrik Dahl)