Four people have been arrested in Peru on suspicion of killing some 60 people to sell their fat and other human tissue to Italian co-conspirators for cosmetic use in Europe, authorities say.

The suspects were arrested in central Peru this month and a search is underway for seven others - including two Italian citizens whose names were not revealed - lead prosecutor Jorge Sans Quiroz said.

The fat was purchased "to be commercialised in European [cosmetology] laboratories," he said.

The prosecutor's indictment said the gang allegedly targeted farmers and indigenous people on remote Andean roads, tricking them by offering them jobs before killing them.

One reported killing took place in mid-September to remove human tissue for trafficking.

The trafficking network could be linked to 60 individual disappearances in the central Andean region, although the ties could not be confirmed.

Police began arrests after discovering early this month a container with human fat that was being shipped to Lima from the Andean city of Huanuco, some 400 kilometres north-east of Lima.

Signs of "an international network trafficking human fat" first surfaced about two months ago, according to General Felix Burga, head of the police criminal division.

Peruvian press cited him as saying the fat can be sold for $US15,000 ($16,325) per gallon in European countries.

The alleged plot revived the Andean legend of the Pishtacos, white foreigners who were said to suck the fat out of people travelling on lonely roads at night, making fine soaps, lubricants, healing salves and beauty creams out of the tissue.

- AFP