Police say Sergio Gomes Moreira Filho, 29, admitted he’d strangled Kyriakos Amiridis to death at the direction of the diplomat’s Brazilian wife.
Investigator Evaristo Magalhaes labelled the killing “a crime of passion.”
The 59-year-old ambassador was missing from Monday to Thursday (December 26-29), when his body was found in a burnt-out car on the outskirts of the city.
Both Moreira and Amiridis’ wife Françoise have been taken into custody.
They are said to have plotted the crime a few days in advance.
Moreira’s cousin has also been detained under suspicion of acting as a lookout while the murder was committed and of helping to carry the body from the house for a promised sum of 24,000 euros.