Police in South Africa have said they are "working around the clock" to catch the killers of a couple who emigrated from south Wales.
The body of Christine Solik, 57, was found 50 miles (80km) from her home in the Kwazulu-Natal province three days before that of her husband, Roger, 66.
Police initially began a kidnap and robbery investigation after a neighbour found bloodstains in their home.
The couple from the Cynon Valley emigrated after their marriage in 1980.
Mrs Solik's mother, Sheila Savage, 83, from Abercynon, Rhondda Cynon Taff, said the family were "devastated".
A passer-by spotted the body of Mrs Solik in a river on Friday 17 February, and a search and dive unit discovered Mr Solik's body last Monday.
Police said Mrs Solik had suffered a head injury, and both of the couple's hands had been bound.
Several teams of officers, including a canine unit, are investigating the murders.
KwaZulu-Natal acting provincial commissioner Maj Gen Bheki Langa said officers would "not rest until the killers are brought to book".
The Times' Africa correspondent Aislinn Laing said people in South Africa were "horrified" by the deaths despite the country's high crime rate.
"In a small community like this it has caused a huge amount of alarm," she told BBC Radio Wales' Good Morning Wales programme.
The couple lived on a farm estate in the town of Nottingham Road, about 100 miles (160km) in land from Durban.
Mrs Savage said the couple had returned home to Mountain Ash in January in order for Mrs Solik to see her father, Glyn Savage, before he passed away.
Members of both families plan to travel from the UK to South Africa on Saturday as the couple's funeral is due to be held in Cape Town on Tuesday.
"They were wonderful parents, had four lovely children, who are obviously suffering now," said Mrs Savage.
"I remember we always had wonderful holidays out there - all of the family - we'd make a special effort."
In a joint statement issued on Tuesday, the couple's four children, Alexander and Gregory, 32, Jessica, 30, and Brendon, 29, said it was "hard to understand that... something so violent could happen".