Preyen said: ”The first officer on the scene contacted me and informed me that Anni had been shot three times at point blank range.
”There were no signs of a struggle or any other interference.”
Preyen, who with Mr Dewani is a director of care home company PSP Healthcare, said his brother was a resilient man who was turning to his faith to help him with his grief.
Paying tribute to Anni, he said: ”She was incredibly beautiful, a smiling, bubbly personality who was excited and keen to embark on life as Mrs Dewani.
”Life was about to start for them. They were excited and it was the time of their lives, like any young couple going on honeymoon.”
Mr Dewani, a former pupil of Bristol Grammar School, and Anni, who was Swedish and worked for mobile phone company Ericsson, had been together for about a year.
After their Mumbai wedding they had flown back to their home in Westbury-on-Trym, Bristol, to celebrate the Hindu festival of Diwali with their family.
They left for South Africa on Tuesday (9/11) and were four days into their honeymoon when tragedy struck.
Mr Dewani, who is being helped in South Africa by his father, Prakash, and Anni’s father, Vinod Hindocha, is expected to return to Bristol in the next few days.
A post mortem examination was completed on Monday (15/11) and Anni’s body will be flown back to the UK for a funeral and memorial service later this week.
It had been widely reported that the couple had taken a diversion to visit the nightlife of the local townships, which are generally considered no-go areas for tourists.
”An outstanding young man”
But Preyen refuted the rumours, and said they had merely been driving along the main road when they were stopped.
Preyen added that his brother had so far been coping with his grief.
He said: ”He is very resilient and has tremendous strength of character. He has always been strong, with a firm belief in the Hindu faith.
”He was the general secretary of the National Hindu Students Forum and after university continued to assist the younger generation in maintaining their culture and religion.
”This now serves to help him in his own hour of grief.”
More than 200 friends and family and members of Bristol’s Hindu community have now visited Mr Dewani’s home to pay their respects to Anni – singing prayers and hymns.
A shrine has also been set up in her honour.
A former teacher at Bristol Grammar School yesterday (Tues) described Mr Dewani as ”an outstanding young man, immensely talented, very diplomatic and a natural leader”.
He studied for a degree in economics and finance at Manchester, before working as a chartered accountant for the consultancy firm Deloitte in London.
Five years ago he and Preyen joined forces to expand the family business, now owning a £15-million empire of award-winning nursing and care homes.
He employs almost 500 people and cares for a similar number of elderly people and those with dementia.
Police in South Africa are still hunting for Anni’s killers, and ministers in the country are appealing for people to come forward with information.
A Foreign Office spokesman said: ”We are aware of the situation and are providing consular assistance to a British national who is involved, and their family.”
Preyen thanked the South African police, the Foreign and Commonwealth Office for their help in the investigation and asked the family now be given time to grieve.
He added: ”We now humbly request that we be given some time and privacy to come to terms with this tragedy without further intrusion.”