Brothers Paul and Barry Channer, both from Greenwich, were seen by officers receiving a suitcase packed with 28 kilos of high-purity heroin from Polish national Waldemar Nowakowski, at South Mimms services last July.
Paul Channer was overheard by police boasting about the potency of the drugs he had bought, saying: "This one is 10 out of 10, so hopefully it will kill a couple of people."
The brothers were stopped by armed officers in east London soon after picking up the drugs, which were believed to have been destined for the streets of the capital, while Nowakowski was arrested early in 2010.
Paul Channer, 47, unemployed, of Vernham Road, SE18, pleaded guilty to conspiracy to supply heroin at Snaresbrook Crown Court on 9/4/2010 and was sentenced to 14 years imprisonment.
Barry Channer, 40, a lighting engineer, of Azof Street SE10, pleaded guilty to being concerned in the supply of heroin on 9/4/2010 and was jailed for 8 years.
Waldemar Nowakowski, 30, unemployed, of Opal Close E16, pleaded guilty to conspiracy to supply heroin on 9/4/2010 and was sentenced to 11 years imprisonment.
Detective Inspector Sarah Staff from the Metropolitan Police’s Serious and Organised Crime Command, said: "This was a long-term proactive operation which has resulted in the dismantling of an organised criminal network.
"The fact that one of these men apparently aspired to kill people with his drugs shows just how callous these dealers were.
"The hugely damaging effects of heroin on society are well documented and it is only right that those willing to profit from its supply face a lengthy prison sentence."
As part of an intelligence-led investigation, during which both the Channer brothers were placed under surveillance, officers followed them as they travelled by car to South Mimms services, close to Junction 23 of the M25 on 23 July 2009.
The pair drove in convoy, Barry in a black Lexus and Paul in a black Mercedes, before stopping at the services to meet a man. He was later identified as Nowakowski and he was seen taking a suitcase from the boot of his own car and placing it in that of the Lexus.
The brothers then left and were later stopped by armed officers on the Blackwall Tunnel Northern Approach,close to Twelvetrees Crescent, E3.
The suitcase was opened and found to contain 28 parcels wrapped in brown tape.
Subsequent analysis showed these to be kilo packages of heroin with a total street value of £1.4million.
Searches of the suspects’ homes and cars were conducted, with small amounts of cannabis, several mobile phones and weighing scales among the items retrieved.
When interviewed at Bethnal Green police station, Paul Channer refused to comment while Barry Channer claimed to be unaware that the suitcase contained illegal drugs.
Following further investigations into his activity Nowakowski was arrested on 13 January 2010. When he was interviewed at Ilford police station, in a prepared statement he denied any involvement in the supply of heroin however he was charged the same day.