A British-Iranian woman arrested in Iran after trying to attend a men's volleyball match has been released on bail pending a decision by the Court of Appeal, her brother said Sunday.

The report quoted Sousan Moshtaghian, mother of Ghoncheh Ghavami, as saying a judge released her daughter on nearly $30,000 bail ahead of an appeal.

"My daughter has insisted in the initial court that she is not guilty," said Moshtaghian. "We are hopeful that she will be acquitted in the appeal court."

Ghoncheh Ghavami, a 25-year-old law graduate from London, "was released on bail just a couple of hours ago and she will stay with my parents" in Tehran, her brother Iman Ghavami told AFP.

The case highlighted limitations placed on women inside Iran and efforts by hard-line authorities to enforce strict interpretations of Islamic norms despite a policy of greater openness being pursued by moderate President Hassan Rouhani.

The mother said Ghavami will be free until an appeals court rules on her case. She confirmed that an initial ruling had sentenced Ghavami to a year in prison for "propagating against the ruling system."

She said the family plans to hire a new lawyer for the appeal. The judiciary has said her case is linked to opposition work, not a volleyball match.

Her brother said that the verdict was handed down a few days ago, and she was sentenced to a year as well as two years of what he said were "travel restrictions".

"She might go back to prison," he said in London.

He said efforts to impose additional charges against his sister had failed and she was in the end sentenced for "propaganda against the regime".

Women are usually banned from attending male-only matches in Iran, however earlier this month sports officials said they have reconsidered the limits and women will be allowed to attend the matches in the future. Ghavami tried to enter the stadium with other women to protest the ban, according to Amnesty International. Female photographers inside the complex were also ordered to leave, though none were arrested.

She has gastrointestinal problems after going on hunger strike, and has also lost weight since being in prison.

"It was unexpected that she was released, it was out of the blue," Iman Ghavami said.

"My parents were trying to ask the judge to issue a medical leave for my sister and then he just decided that she should be released on bail."

He said he had managed to speak to his sister for "just a few seconds -- I think she sounded happy".