Teddy Tomaro, sentenced to life in prison for killing Luc Ethier, was freed and cleared of all charges, Abdul Majeed Khuraibet told AFP.
Ethier’s wife, Mary-Jane Bitos, who was sentenced to three years in prison for giving false testimony, was also set free, along with Norasa Talib Esick and Lourdes Viray.
Esick had been sentenced to five years in prison for adultery and possession of a firearm, while Viray got three months in jail for not reporting the crime.
"Justice has been served," Khuraibet said. "By 5 p.m. today they will all be released. All the charges have been dropped by the court of appeals and everybody is innocent."
The verdict was announced at 10:45 a.m. local time, Khuraibet said, but none of the defendants was there to hear it.
Jimmy Binuya and Rosalia Tesoro Baclig, two other Filipinos charged in the case, were acquitted by the criminal court in May.
Ethier was shot dead as he walked with Bitos through a busy shopping area south of Kuwait City on Oct. 10, 2001.
The murder raised fears among the expatriate community in Kuwait of a revenge attack on a Westerner following the Oct. 7 launch of US-led air strikes on Afghanistan.
Both Ethier and his wife had converted to Islam.