A 15-year-old girl who faced 100 lashes in the Maldives after she was raped by her step-father has had the sentence overturned following an international campaign.

The child, who cannot be named, was handed the draconian flogging sentence for “fornication” in February, triggering a petition by the global campaign network Avaaz and anger from opposition and women’s rights groups in the country. Two million people worldwide signed the petition calling for the sentence to be commuted.

Last week, the Maldivian High Court overturned the sentence, which was hailed as a victory by Avaaz. But the organisation said that the case was a one-off and called for a moratorium on all flogging sentences in the Maldives, which is under the Islamic government of President Mohammed Waheed Hassan.

The girl has been under house arrest on an island near the capital Malé since her sentence. She is now free but campaigners hope she will remain in the care of the state to continue her education, rather than be returned to her family where she could be at risk of further abuse.

Presidential elections take place early next month and the opposition party, the Maldivian Democratic Party, has been campaigning for an end to harsh sentences against women, many of whom are rape victims. Women and girls face a struggle to be regarded as victims, rather than complicit perpetrators, of gender-based crimes.

The 15-year-old girl’s case was highlighted by The Independent on Sunday last month, when opposition MPs called on David Cameron to do what he could to put pressure on the Maldivian government. Alongside the petition, Avaaz launched a poster appealing to the 500,000 tourists, including many British honeymooning couples, who travel to the “paradise” islands every year to consider the damaging effect on women’s rights by such sentences.

It is possible that the issue of flogging sentences in the Maldives will arise in the Commonwealth Heads of Government meeting in Sri Lanka in November – as well as human-rights issues in the host country.

The Maldives High Court said it was overturning the sentence because the girl denied “confessing” to consensual sex outside marriage.

Alaphia Zoyab, who has led the campaign on behalf of Avaaz, said last night: “This is great news that her flogging sentence has been overturned and that she no longer faces house arrest. The reason this is a big deal is we are talking about a 15-year-old child. She is a child. A lot of people have said she knew what she was doing, but she is a child.

“It is still just a one-off case, however. I strongly believe the overturning of the sentence is down to the spotlight being put on this case. But wider systemic problems remain – the courts can continue to hand down sharia sentences of flogging. Flogging can change to stoning. Sharia law is not codified in the Maldives, so it is still down to the courts to decide. So this is a great victory, but it is a one-off.

“We want to see a moratorium on flogging. We want the Maldives to live up to its international obligations. We are waiting and watching to see what happens in the elections, and which government we can engage with.”