A vicious crocodile killed a housewife washing clothes in a river - then later mauled her son to death when he tried to search for her.

Alvina Doki, 64, was doing her family's laundry in the Ledewero River when the beast emerged from the turbid waters and attacked her in East Nusa Tenggara province, Indonesia, on February 5 afternoon.

Her husband Gabriel Sinyo, 60, said he swung around upon hearing a 'suspicious rippling sound' - only to see his wife trapped in the croc's jaws. He pelted the large reptile with rocks he scooped up from the riverbank, but it dragged Alvina away into the depths.

The family reported the attack to local police and a search team was dispatched to the area.

Henry Novika Chandra, commissioner of the regional police, said: 'The victim was attacked by a crocodile while washing clothes. Currently, her body has not been found. Our members together with the local community are still continuing the search. Hopefully the victim's body will be found soon.'

Volunteers and villagers, including Alvina's son Wilsilius Lomi, 35, were still combing the river in the evening.

However, the sinister predator's rampage continued that night, when it returned to the river and pounced on the frantic son, who had separated himself from the group in a desperate attempt to cover more search area.

Horrified residents watched as the crocodile snapped up the young man before disappearing underwater. His body was found floating in the river at 10 am the next day, February 6.

Assistant Police Commissioner (AKP) Yusuf Tarapadjang said: 'We finally found Wilsilius' body about 500 metres from where he was attacked. His body had a number of claw and tear wounds. The body was intact, there were only wounds on the legs and stomach from being attacked by the crocodile.'

The young man's corpse was taken to his home to be buried.

Authorities said the search continues to find Alvina's body.

The Indonesian archipelago is home to 14 types of crocs - with a large population of extremely large and violent estuarine crocodiles that flourish in the region's climate.

Conservationists believe that crocodiles have been driven further inland closer to villages due to overfishing reducing the crocodiles' natural food supplies combined with habitat loss from the development of coastal areas into farms.

Widespread tin mining has also caused villagers to encroach on the crocodiles' natural habitats, pushing the creatures closer toward people's homes.

With uneducated locals in the developing country still using rivers for bathing and primitive fishing, the deadly combination of factors has led to rising numbers of crocodile attacks.