A British-Iranian aid worker accused of causing the death of a young Indian boy has been acquitted on appeal.

Narges Kalbasi Ashtari was convicted in 2014 and jailed for a year over the death of five-year-old Asim Jilakara, who disappeared from a picnic she had organised.

It is thought Asim was swept away by a strong current. His body was lost.

Ms Ashtari, 28, denied causing death by negligence and has been on bail pending the outcome of an appeal.

She said she gave a statement about the death to the police on the day, but a month later officers filed a complaint against her, insisting that she had thrown the boy into the river.

Jilakara's mother accused the aid worker of killing her son, but Ms Ashtari maintained that she was caught up in local corruption after she refused to pay bribes to local officials after the accident.

She was banned from leaving India during her appeal, which drew the attention of international aid organisations. An online petition about her case was signed hundreds of thousands of times.

On the petition she wrote: "I have gone through the most horrific forms of abuse by a group of people with immense power, influence and protection."

Iranian Foreign Minister Mohammad Javad Zarif welcomed the acquittal in a post on his Instagram account.

He said: "I felt happy about the news of the acquittal of the benevolent Iranian lady Ms Kalbasi. Greatest congratulations to Ms Kalbasi and regards for her because of her patience and perseverance, and thanks to colleagues and [the Iranian] people's campaign in her support."

Born in Iran, Ms Ashtari moved to the UK when she was four and then to Canada to live with her aunt after losing both her parents.

She moved to India in 2011, to Mukundapur in Orissa, one of India's poorest states, where she established a foundation for orphaned children.