A Frenchman and a Thai woman were found shot dead and another Frenchman wounded at a cold-meats company in Sukhumvit area of Bangkok on Wednesday.
Thong Lor police said the shooting occurred at Flying Board Thailand Co on Soi Sukhumvit 49/6 around noon.
Pol Maj Gen Chokchai Ngamwong, deputy chief of the Metropolitan Police Bureau, said police called to the scene found the body of a dead Frenchman in the kitchen on the ground floor of the three-story building. A dead Thai woman was found in a cold storage room on the same floor.
Both appeared to have been shot with the same weapon, a 9mm pistol, he said.
They were Marc Lohberger, 66, and Wiranya Meeyai, 43, according to a police source.
Pol Maj Gen Chokchai said another French national, 60, was lying wounded, also on the ground floor. He was taken to Samitivej Hospital, and was in a safe condition.
He was later identified as David Bouton, 48, according to the same source.
Pol Maj Gen Chokchai said investigators were still trying to piece together what happened, and the motive for the shooting.
Flying Board Thailand Co supplies cold cuts including sausages, bacon and beef to restaurants and hotels. The wounded man, Mr Bouton, is one of the partners, according to police. It has been operating for two years.
An assistant chef at the company told police that she heard the two Frenchmen quarrelling in French, and then the sound of gunshots.