Officers believe the boxes were being used to store criminal assets
Six suitcases packed with suspected gold dust and about £30m in cash have been found during searches of safety deposit centres in London, police say.
Detectives also found heroin and cocaine, evidence linked to child sex abuse and forged passports.
The Met Police believe criminals used the centres in Park Lane, Hampstead and Edgware to store criminal assets.
Armed police continue to guard the buildings as specialist officers search the 7,000 safety deposit boxes.
So far only a third of the boxes have been opened and the finds have also included a firearm, counterfeit currency, several works of Renaissance art and a substantial amount of high value jewellery.
Speaking after the raids Commander Allan Gibson said: "Search teams have been working around the clock to open all the boxes at the location and are progressing well, although we are likely to remain at the locations for some time yet.
"This is a complex and unique investigation that will use all of the expertise within the economic crime command and the findings are within our expectations at this stage.
"I am confident that this operation will have a damaging impact on organised crime in London and around the rest of the country."
Scotland Yard said that Met's Specialist Crime Directorate raided seven properties in total on Monday 2 June as part of Operation Rize - three safe depositories, an office and three residential addresses.
Two people were arrested on suspicion of money laundering offences.