Nearly 200 people have been arrested and £13.4 million in cash has been seized in London after the National Crime Agency, working with the Met Police and European partners, cracked an impenetrable military grade crime chat network.

The Met Police say the break-through has allowed officers to disrupt murder plots and arrest some of London's longest standing and most dangerous criminals.

"Untouchable" kingpins posing as wealthy tycoons are among nearly 200 people arrested in London after the National Crime Agency, working with the Met Police and European partners, cracked an impenetrable crime chat network.

The Met Police say the break-through has allowed them to disrupt murder plots, seize £13.4 million in cash and arrest hundreds of top-tier criminals in the capital in their "most significant operation to date."

Richmond and Twickenham Times:

Major London crime figures, including previously "untouchable" kingpins leading flashy lifestyles "beyond the MPS' reach", were among 800 Europe-wide arrests after messages on EncroChat had been intercepted and decoded.

The investigation was initiated by Dutch and French police, with Europol, Europe's agency for law enforcement, working with a number of other police forces to bring down large networks of crime.

After four years of work, French investigators were able to access Encrochat, an encrypted military grade communications system used by 60,000 people worldwide, for purely criminal purposes.

Led by the NCA along with police forces across Europe, the Met Police said it was the most significant operation they have ever launched against serious and organised crime.

Wil van Gemert, deputy executive director of Europol, told a press conference in the Hague that the hacking of the network had allowed the "disruption of criminal activities including violent attacks, corruption, attempted murders and large-scale drug transports".

Richmond and Twickenham Times:

The Met Police Commissioner, Dame Cressida Dick, whose force made 171 of the 746 UK arrests and seized £13.3m in cash, described it as a "game changer."

She said: "This is just the beginning. We will be disrupting organised criminal networks as a result of these operations for weeks and months and possibly years to come."

Richmond and Twickenham Times:

Nikki Holland, NCA director of investigations, said the operational team had described it "as akin to cracking the enigma code".

"They see this as that significant in terms of getting that inside information, effectively having a person inside an organised crime group telling us what they're up to," she said.

An estimated 60,000 people, among them up to 10,000 in Britain, subscribed to the France-based EncroChat, which has now been taken down.

The system operated on customised Android phones and, according to its website, provided "worry-free secure communications".

Richmond and Twickenham Times:

According to the Met Police, international partners successfully managed to access and dismantle Encrochat, and shared its data and messages with the MPS.

The company, which charged £1,500 for a device on a six-month contract, sent out a warning to users in early June to say that its servers had been hacked by a government entity.

This left investigators with a race against time to make the most of the wealth of information available on the platform, targeting "Mr and Mrs Bigs" before they could cover their tracks.

Thousands of police officers from the NCA and every police force in the UK were involved in the subsequent international sting that was launched in April.

In London, the data revealed that there are approximately 1,400 users of Encrochat in the capital, all using the encrypted communication system to securely communicate on a platform that was until now impenetrable.

The Met the launched an operation codenamed 'Eternal' to target criminal users, with special detectives working relentlessly to monitor hundreds of handsets and encrypted messages to build dozens of cases.

Richmond and Twickenham Times:

The police force said: "The operation has revealed the criminality of individuals who were previously unknown to the MPS, as well as provided evidence to prosecute a significant number of known criminals who regarded themselves ‘untouchable’ and remained beyond the MPS’ reach – until now.

"This operation has enabled detectives to place these individuals at the centre of networks of criminality."

So far, the MPS has achieved results in 38 separate investigations under this operation and arrested 171 people for offences including conspiracy to murder, possession of firearms, money laundering and conspiracy to supply Class A and B drugs.

Richmond and Twickenham Times:

A total of 110 people have been charged so far, and officers have seized more than £13.4 million in cash - £5 million of this in one operation alone. This is the largest single cash seizure the Met has ever made.

Officers have recovered 16 firearms, including Scorpion submachine guns and revolvers, seized more than 500 rounds of ammunition, 37 encrypted devices, 620kgs of Class A drugs and 19kgs of Class B drugs.

One investigation led to several arrests of people identified as being part the most high-harm organised crime group in London, with long-standing links to violent crime and importing Class A drugs.

The central figures of this group lead lavish lifestyles and live in multi-million pound properties with access to top of the range vehicles, appearing to be successful, respectable business people but are actually dangerous individuals.

Another investigation saw detectives infiltrate and prevent a planned hit job on a rival group member, and the Met say further results from the operation will be emerging in the coming months.

Commissioner Cressida Dick said: “This operation is the most significant activity, certainly in my career, we have ever carried out against serious and organised criminality across London.

“Organised crime groups have used encrypted communications to openly discuss plots to murder, launder money, deal drugs and sell firearms capable of causing atrocious scenes in our communities. They were brazen and thought they were beyond the reach of the law.

"This operation has enabled us to target those at the top of the hierarchy and individuals we have known about for years but have not been able to tackle head on."