Fariman Khan and Francis Cooper were arrested last autumn following a lengthy investigation by the National Crime Agency’s Armed Operations Unit.
Cooper had driven a white transit van to Streatham in South London in July 2016 to meet with 41-year-old Carl Stanley.
Officers observed Cooper hand something to Stanley before the pair both drove away in separate vehicles.
Stanley’s vehicle was stopped by officers from the Metropolitan Police Service in the same street and he was arrested on suspicion of possession with intent to supply a class A drugs.
They found what was later confirmed to be approximately 2kg of heroin, with an estimated street value of £198,000.
The unit investigated the handover and identified Khan as the facilitator of the drugs exchange.
Khan, 46, and Cooper, 61, both of Reynolds Avenue, were arrested in October 2017.
Officers searched the property in Reynolds Avenue, recovering a number of mobile phones, SIM cards, computer devices and more than £69,000 cash in the process.
Cooper pleaded guilty to conspiracy to supply class A drugs at an earlier hearing on April 10 and Khan was found guilty of the same offence yesterday following a trial at Leeds Crown Court.
Both men have been remanded in custody until sentencing on August 3.
Stanley, of Cameron Place, London, was jailed for four years in January for possession of heroin with intent to supply.
Senior investigating officer Tim Gregory said: “Khan has an extensive criminal history and seemingly no respect for law enforcement as he continued to offend while on licence from prison.
“He and Cooper have been found guilty of supplying vast amounts of class A drugs across the UK – drugs which fuel further crime, violence and exploitation and I have no doubt the public are safer now they are both behind bars”.