Argibeaut said: "Samuel was waiting for me with four other people.
"He gave me a headbutt which hit me on the forehead and the lip.
"They then took off my shoes, which in Cameroon means I am threatened with death," Argibeaut was quoted in daily sports newspaper Marca.
Argibeaut said he had been in Mallorca to reclaim money from the 21-year-old former Real Madrid player.
Eto'o is expected lead Cameroon's attack in the World Cup.
He was recently charged by the Spanish football federation disciplinary committee for headbutting Valencia forward Miguel Angel Angulo after the 1-1 with Mallorca on April 13.