British organised crime groups are collaborating closely with former international rivals like the Italian mafia to import increasingly bigger cocaine shipments into Europe, a senior investigator has revealed.

Lawrence Gibbons, drug threat lead at the National Crime Agency, said there was evidence that British gangs were forging an increasingly collegiate relationship with other powerful European crime groups, a notable development in the traditionally hyper-competitive world of cocaine trafficking.

Gibbons, who has 40 years’ experience in the field, said the NCA had begun finding large cocaine consignments in the same shipping container that appeared to be divvied up between criminal groups from different countries, which had joined forces to share the same sources and logistics.

This means that UK gangs are working in tandem with groups like Italy’s powerful ‘Ndrangheta mafia clan, which controls much of Europe’s cocaine trade.

Such a relationship allows British-based groups to tap into the huge buying power and contacts of one of the world’s richest criminal groups. In 2013, Europol estimated the ‘Ndrangheta’s turnover was GBP44bn — greater than McDonald’s and Deutsche Bank combined.

The development may also explain why shipments of cocaine to the UK appear to be growing in size. It comes days after the NCA helped intercept a huge two-tonne cocaine shipment from a yacht off south Devon, which led to its six crew being charged.

Gibbons told the Observer: “Instead of Mr Bigs operating totally independently like they did 10 years ago, there are a lot more OCGs working together. There is a collaboration between them, a collaboration at source with people sharing routes, transportation and containers.”

NCA analysis indicates 1,716 British organised criminal groups are involved in drugs supply, a number of which buy cocaine direct from the South American cartels using intermediaries or sources forged by the ‘Ndrangheta, along with corrupt officials at ports like Rotterdam and Antwerp, where the drug often arrives into Europe.

Evidence that the major crime groups are working together suggests Europe’s huge cocaine market has grown large enough to sustain its major players alongside each another. South American cartels in countries such as Colombia prefer to export cocaine to Europe because it avoids the heavily policed US border and dealing with the violent Mexican cartels.

Gibbons said that cocaine is now widely used throughout UK society, challenging outdated claims that it remains the preserve of the middle classes.

In August the home secretary, Priti Patel, urged police to “make an example” of middle-class cocaine users in a new crackdown, promising to “name and shame” wealthy users.

“It’s a drug used by everyone from the highest levels of society to the lowest levels of society. It is no longer the drug for people with a lot of money behind them,” said Gibbons.