The raids also seized weapons and ammunition
Hundreds of British and Afghan troops have seized heroin and drug-making chemicals in Afghanistan with a street value of more than £50m ($71m).
Defence Secretary John Hutton praised the troops' bravery and said the seizures in Helmand province would starve the Taleban of funding.
The raids on four drug factories, involving 700 troops, would also stop the drugs reaching UK streets, he said.
Mr Hutton said there was now more "security and governance" in Helmand.
News of the raids came as the BBC obtained emails from a UK official working in Helmand estimating that 60% of Afghan police in the province use drugs.
'Starve Taleban funding'
Operation Diesel, which took place between 6 February and 11 February, also disrupted facilities making improvised bombs.
Mr Hutton said: "Our dedicated and professional forces have once again taken the fight to the enemy.
"Their bravery, coupled with the size and sophistication of our firepower, has cleared the enemy from large areas of Helmand bringing security and governance to more of the province.
"The seizure of £50m worth of narcotics will starve the Taleban of crucial funding, preventing the proliferation of drugs and terror on the UK's streets."
Troops destroyed 1,295kg of wet opium, estimated to have a street value of more than £6m as heroin.
Also found were chemicals used in the manufacture of heroin - ammonium chloride, acetic anhydride, sodium chloride and calcium hydroxide - in sufficient quantities for the production of drugs with an estimated street value of more than £50m.
Troops also seized weapons and ammunition, including rifles, machine guns, three rocket launchers with additional warheads, and a motorbike modified for use in a suicide attack.
The commander of Task Force Helmand, Brig Gordon Messenger of the Royal Marines, said: "The links between the Taleban and the drugs trade are well proven and we know that the revenue from narcotics production directly funds the insurgency.
"Operation Diesel was a clinical precision strike, supported by strong intelligence, which has had a powerful disruptive effect on known insurgent and narcotics networks in the area.
"The success of the operation is a significant boost to the Afghan authorities in their fight against the drugs trade."
Operation Diesel involved Afghan Security Forces and British troops from 45 Commando Royal Marines, 42 Commando Group Royal Marines, 3 Commando Brigade's Reconnaissance Force, 1st Battalion The Princess of Wales Royal Regiment and the Armoured Support Group.