London : The Metropolitan Police Service has seized about £180 million ($249 million) in cryptocurrencies, the largest seizure in the United Kingdom, according to the force.

The seizure is believed to be one of the greatest in the world, according to the Met Police, and comes just weeks after officers seized £114 million ($158 million) in cryptocurrencies in June.

The seizures were made by the force's economic crime command after intelligence about the transfer of illegal assets was acquired, according to a news release released Tuesday.

The seizures were made as part of an ongoing international money laundering investigation.

Cryptocurrency is a digital money system comprised of "coins" or "tokens" that are managed via a decentralised ledger.

The type of cryptocurrency seized has not been disclosed by the police.

On June 24, a 39-year-old woman was arrested on suspicion of money laundering and freed on bond, according to police.

She was questioned under oath on July 10 in connection with the recent discovery of approximately £180 million and has been released on bail until later this month, according to the force.

The seizure earlier this month, according to Detective Constable Joe Ryan, was a "major milestone" in an ongoing operation.

"We successfully seized £114 million in cryptocurrency less than a month ago. Since then, we've been conducting a complicated and wide-ranging investigation "he stated

"We've put in a lot of effort to track down this money and figure out what criminal activity it might be tied to. Today's confiscation marks yet another critical milestone in this investigation, which will continue for months as we zero in on people at the heart of this alleged money laundering conspiracy "Ryan went on to say.

"Proceeds of crime are laundered in many different ways," said Deputy Assistant Commissioner Graham McNult in a statement. While cash is still king in the criminal world, we're seeing more and more organised criminals use cryptocurrency to launder their filthy money as digital platforms advance.

"While this was relatively uncharted ground a few years ago, we now have highly trained police and specialty units working hard in this space to stay one step ahead of those seeking unlawful gain."