Daniel Kelly and Steven Gilhooly, both 43, used canned goods to try and ship around 2.74kgs of cocaine with a street value of more than £250,000.
When they were forensically examined it was discovered that within the first parcel was 1.95kg of cocaine and in the second 792g of cocaine.
The National Crime Agency (NCA) and Met were already probing Kelly and Gilhooly and discovered they bought a machine can sealer and blank tin lids in order to reseal tin cans.
They also purchased a string of condiments and other goods that would be sold in St Lucia.
Four days before the first parcel arrived in the capital, Kelly and Gilhooly flew from Gatwick to St Lucia, where they told officials they were arriving for a holiday and border authorities recorded they had the can sealer in their luggage.
Officers later discovered the two cocaine parcels were sent from a St Lucian Post office by Kelly, who used a fake driving licence that had his image but false personal details as ID.
Kelly was sentenced to six-and-a-half years in prison Wednesday, while Gilhooly was jailed for eight-and-a-half years for importing class A drugs into the UK.
Detective Inspector Matthew Webb, of the Met Police Specialist Crime team, said: “This should send a clear and strong message to those intent on penetrating our borders that offences of this nature are taken very seriously and we will leave no stone unturned in bringing them to justice.
“Both men travelled to St Lucia with the sole purpose of importing class A drugs back into the United Kingdom.
“The miserable effect that drugs supply has on our communities is undeniable and inextricably linked to violence within our communities.
“Both men were willing to take such a risk with this offending - thinking they were beyond the reach of the law and hoping to monetise profits.
“Instead, they now face hefty prison sentences. I hope this provides them the opportunity to reflect on their behaviour and demonstrates that crime doesn’t pay.”
Additional reporting by SWNS