The National Crime Agency investigated Dalton Anderson, Alvin Russell and Sinclair Tucker after Birmingham-based organisation Vision Christian Ministries (VCM) was used to smuggle the drugs – worth up to £2m when sold in the UK.
The cannabis was trafficked from Jamaica to the UK, via Birmingham Airport, and had been packed into sealed tins of Calaloo, a Jamaican green vegetable, and Akee fruit.
It was shipped in three separate consignments addressed to VCM between March and May 2017 and seized by Border Force.
Anderson, 50, of Groveland Road, Tipton; Russell, 45, of Wood Lane, West Bromwich, and Tucker, 64, also of Groveland Road, Tipton, were arrested at the airport on May 23 of that year, while inspecting the third consignment which had just arrived.
NCA investigators established that they organised the imports and collected the drugs from the airport.
Anderson and Russell also spent some time in Jamaica when the importations were made, handling money and providing shipping documentation to VCM via Tucker.
All three were charged with conspiracy to import class B drugs – cannabis, with Anderson also charged with possession with intent to supply class B drugs after five kilos of cannabis was found at his home following his arrest.
Anderson was convicted at Birmingham Crown Court on November 29, with the other two found guilty on Wednesday, following a five week trial.
They are due to be sentenced at the same court on January 27 next year.
NCA operations manager Rick Mackenzie said: “Anderson, Tucker and Russell cynically used a Christian ministry as a smokescreen to import huge quantities of cannabis into the UK.
"They wrongly believed that this would put them beyond the reach of the National Crime Agency and our law enforcement partners.
“The NCA works closely with Border Force to disrupt and dismantle criminal networks involved in drug trafficking.”
Assistant Director Inland Border Command for Border Force Paul Harper said: “This was outstanding work to stop £2 million worth of drugs reaching Britain’s streets and causing further harm to our communities.
“This seizure and others like it send a clear message to anyone considering attempting to smuggle illegal drugs into the country that we remain committed and prepared to tackle drug supply chains.”