'Everyone is concerned about Shrien's mental health – but not about getting justice for Anni'

The sister of murdered bride Anni Dewani describes her family's torment to Terri Judd

The Hindocha family reacted with their usual compassion and dignity as they emerged from court 10 days ago after yet another delay to Shrien Dewani's extradition but, as Anni's sister has revealed, it was another moment of tortuous frustration in the family's long journey to find out what happened in South Africa.

Ami Denborg was the quieter of the two sisters, happier to watch her younger, vivacious sibling enjoy the limelight. Yet the engineer and mother-of-two, has become the voice of the Hindocha family through the slow legal process to have Mr Dewani extradited to South Africa accused of the murder of his bride.

When judges halted his extradition at the eleventh hour, agreeing with his lawyers that his depression and post traumatic stress made such a move oppressive, the family simply reiterated their plea for justice. But speaking to The Independent, Mrs Denborg, 34, revealed the true turmoil of that day. "It is torture for us," she said, "We have been waiting so patiently. We are back to square one.

"It is really frustrating. It is all up to his health. For 18 months nothing has happened. He has not improved, or has he? His conditions are not untreatable. How come they are not making him better? We all felt very, very sad and despondent because we just want the truth."

Anni Dewani had just enjoyed a spectacular wedding in Mumbai and was honeymooning in Cape Town on the night of 13 November 2010 when the taxi driver took the couple through the township of Gugulethu. The car was hijacked and Mr Dewani insists he was ejected along with the driver Zola Tonga. His 28-year-old wife's body was found the following morning in the abandoned car, her life ended by a single shot to the neck.

Tonga later admitted to the crime, claiming as part of a plea agreement Mr Dewani, 32, had ordered the hit, and the South African authorities called for the husband to be extradited to face charges of murder, kidnapping, robbery with aggravated circumstances and obstructing administration of justice. But lawyers for the Bristol businessman have argued he is unfit to stand trial in South Africa.

Despite their dignified demeanour at every court hearing, the strain on Mrs Denborg's face offers a hint of the paralysing grief the family has endured.

"We are still struggling with the fact she has gone," she said. "I miss my little sister so much. I look at my family today and all I can see is what's missing. She was so talkative, so sociable, so bubbly."

Her husband Henning, she said, had been incredibly supportive and she has found some solace in her two children, William, 5, and Alicia, 4. It is watching her parents Vinod, 63, and Nilam's grief that has proved most heart breaking.

At their home in Mariestad, Sweden, they light a candle in Anni's memory every morning. "Her bags are still there. They can't open them without breaking down. Her room's untouched. To see your parents so broken is hard and there's nothing my brother Anish and I can do to help deal with the pain. You can see it in my father's eyes. He is devastated."

The 12 March would have been Mrs Dewani's 30th birthday and the family returned to Lake Vanern in Sweden, where they spent their childhood holidays and where her ashes are scattered.

Dealing with their grief under constant press scrutiny, Mrs Denborg said, had been a difficult learning curve: "I'd never had any contact with the media before... It is just part of my life now."

She still struggles with the fact her sister had second thoughts about the marriage and the family convinced her it was simply last minute nerves. "I think about it, if I had not told her to go back, maybe she would be alive today."