Police have raided addresses in and around London and arrested 22 people in an operation aimed at "dismantling" a £100m drug trafficking operation.
Police used a digger to break through a wall during one raid
About 500 police officers were involved in raids on 30 homes and business premises and 111 kilograms of cocaine, worth £5.5m, was seized.
At one fortified house a digger was used to smash through a perimeter wall.
Detective Superintendent Steve Richardson said the raids had struck a "huge blow" to the drugs industry.
He said the network were believed to have processed around £100m in the last six months, most of it believed to be the proceeds of drug trafficking.
Police seized large quantities of cash and a number of guns during the raids at addresses across London, Surrey, Essex, Kent and Hertfordshire.
At a house in Hillingdon, west London, a police driver used a digger to break through the brick and steel perimeter wall shortly after 0500 GMT as a police helicopter hovered overhead.
Dozens of officers using sledgehammers and angle grinders burst into the house seconds later.
A 40-year-old man was arrested and several vehicles, including two Mercedes, a Hummer and a four-wheel drive Porsche parked outside were seized.
At another address in West Molesey, 30 officers burst into a house and searched two cars outside. A 54-year-old man of Egyptian origin was arrested.
Detectives said they believed a business had been used as a front for a massive criminal enterprise which involved laundering money from the proceeds of trafficking in cocaine and cannabis.
Police said those involved were from a variety of backgrounds. Some were "born and bred Londoners" while others were Irish, Israeli and Iraqi nationals.
Det Supt Richardson, who headed Operation Eaglewood, said: "Today's operation has been hugely successful. We have targeted the key players in a serious and organised criminal network culminating in a huge blow to the illegal drugs industry in the UK.
Police arrested 22 people during the early morning raids
"These criminals have been living the lives of wealthy businessmen through criminal activity and today we have put a stop to this. We believe this network has been supplying drugs around the country, earning millions of pounds every week."
He said the investigation had succeeded in "taking out a group of ruthless and determined criminals who sought to profit from the sale of illegal drugs".
Detective Inspector Martin Ford said the gang used a small number of bureaux de change to launder their "dirty money".
The raids took place across London and the south east
He said: "They have been laundering between £3m and £4m a week. They will take a suitcase full of £10 and £20 notes and exchange it for 500 euro notes.
"The beauty of the 500 euro note is that it's the highest denomination that is universally accepted. So they can convert a suitcase-worth of sterling into a quantity of euros which will fit in a small box."
Police said they believed at least one of the bureaux de change was involved in the criminal enterprise.
Among the other raids were:
An address in Willesden, north west London, where drugs and a gun were seized. A man and a woman were arrested.
A gun, a pepper spray and £2,000 in cash was found at a house in Beckenham, Kent. A man aged 54 was arrested.
Homes were raided in Hayes, Brentford, Twickenham, Stanmore and Pinner, all in west London; Ilford, Essex; South Oxhey and Rickmansworth, both in Hertfordshire; Chertsey, Surrey.