The tourists who were found stabbed to death in a crocodile-infested river in South Africa have been identified as retiree Ernst Marais and his wife Dina.Mr and Mrs Marais, 71 and 73, had driven some 1,100 miles from their retirement village in Mossel Bay on the Western Cape coast for a safari holiday at the country's top nature reserve, the Kruger National Park.The sanctuary is home to the so-called 'big five' for animal spotters: the lion, leopard, rhinoceros, elephant, and African buffalo. Investigators fear the Maraises met their end after encountering illegal poachers at an elephant crossing. A huge manhunt is now underway to find their killers.The couple was staying close to the Kruger's Parfuri Gate in the north of the reserve: staff raised the alarm last week when the couple failed to return to their overnight accommodation.Their bodies were found in the Kruger's croc-infested Limpopo River by tourists visiting at a viewing spot known as Crooks' Corner. Their green Ford Ranger pick-up truck was nowhere to be found.Crooks' Corner earned its name as a one-time operating base for ivory poachers, gun runners, slave traders and murderers on the run, historically a piece of no-man's-land between South Africa, Zimbabwe and Mozambique.It is believed the couple's hands had been tied behind their backs and they had been repeatedly stabbed in the upper body before being dragged to the Limpopo River and dumped for the Nile crocodiles. Ernst and Dina Marais were found dead in a crocodile-infested river in what is thought to be the first murder in South Africa's biggest nature reserve The couple are feared to have encountered illegal poachers at an elephant crossing near the notorious Crooks Corner within Kruger National Park