The men were arrested in 2021 while testing weapons at an old shooting range in Accra, and intelligence telephone taps led to a blacksmith shop, where they ordered the weapons manufactured, according to court documents.

They had all pleaded not guilty during the trial. Police posted a heavily armed units outside the high court for the hearing and sentencing.

The high court, however, acquitted a police chief Benjamin Agordzo, army officer Colonel Samuel Kodzo Gameli, and one other junior military officer, Corporal Seidu Abubakar.

"We give glory to God. He alone has made it happen. They knew it was falsehood. Our God doesn't fail. I have always been free within my heart and I knew how it was going to end," a visibly elated police chief Agordzo told the media following his acquittal.

The six, including a gunsmith and a civilian employee of the Ghana Armed Forces, were charged with conspiracy to commit treason in 2021.

Ghana's attorney general Godfred Yeboah Dame who led the prosecution hailed the outcome of the trial.

"It is a significant judgment because the constitution of Ghana as the fundamental law of the country, which has sustained the stability of the nation, frowns seriously upon any attempt to overthrow a government and that is why that offence [treason] is punishable by death," Dame told the media after the trial.

According to court documents, the men were arrested at their base in the capital Accra with locally-manufactured guns, improvised explosive devices (IEDs) and AK-47 rifles and other ammunition.

Dame said the accused belonged to an association called Take Action Ghana (TAG) and had planned to stage demonstrations, ostensibly to topple the government.

It is the first treason trial in Ghana since 1963 when the first president Dr Kwame Nkrumah was overthrown. Ghana last executed a criminal under the death penalty in 1992 when it returned to constitutional rule.

The new ruling comes as the West African country, known for its stable democracy since 1992, faces heightened security while the wider region has seen a spate of coups in recent years.