Three heroic sisters were found dead after saving a seven-year-old girl from drowning in a river in Thailand.

The trio, twins Champa and Champee,18, and their sister Nan, 14, went to a river to cool down during the hot weather with five other friends as temperatures soared pat 30 degrees Celsius in Kanchanaburi province on March 16.

While they were playing, a seven-year-old girl slipped into the deeper part of the fast-flowing Kwai Noi river so the three girls jumped and tried to save her. They were able to push the youngster to safety but the three sisters were swept away.

More than 50 rescuers and concerned locals joined the search and rescue operation hoping to find the girls alive until their bodies showed up two days later, several miles away from where they were last seen.

Rescue diver Chokchai Namkaew, 26, said: 'We had some difficulties finding the girls because the Vajiralongkorn Dam was scheduled to release water. The rive became deeper and the current more violent.'

The body of Champa was discovered floating in the middle of the river almost 10 kilometres away from the spot she went missing while Nan’s body was found two kilometres away. Champee’s body was the last to be discovered, three kilometres away on March 18.

A concerned neighbour, Yee, attempted to rescue the girls but could not swim through the strong currents and was pulled by rescuers when they arrived. Yee and the seven-year-old who the three girls saved were given first aid and rushed to a hospital by the rescue team.

The team took almost two days before finally discovering the bodies as the Vajiralongkorn Dam water was being released, resulting in violent water flow.

Officers returned the bodies of the three children to their devastated parents and families for religious ceremonies at Wat Wang Phra Wiwekanaram in Mu Si, Sai Yok subdistrict.

The girls' mother Noi, 36, said: 'I was excited for them to come home that day. I cooked their favourite food. I could not believe it when my husband came home instead and told me about it. I don't know how to move on. They were such kind girls.'

A religious ceremony would be held for the heroic girls at a local temple while the neighbour Yee was still in critical condition at the hospital. The seven-year-old girl whom the sisters saved had been discharged from the hospital.

Just two days before the incident, a 13-year-old boy was also found dead in the same river after he fell while crossing an old bridge.