A total of 16 people were arrested on suspicion of money laundering offences in connection with an ongoing financial investigation.
Three warrants were executed on Thursday September 8 in Bradford, Shipley and Leeds.
Two further warrants were executed at addresses in Curzon Street and Hatton Gardens in London.
Five court orders were also carried out in Birmingham, Sheffield and Manchester.
A total of 16 people have been arrested on money laundering offences and are all now on police bail.
A West Yorkshire Police spokeswoman said: “A substantial amount of cash and gold was seized during the operation.”
Enquiries are ongoing.