Three men arrested amid an investigation into international money laundering have been released on bail.
The men, aged 53, 37 and 20, from west London, who were brought to police stations in the Humberside Police area on Wednesday, must return in February.
Police also revealed that cash running into hundreds of thousands of pounds had been seized from several addresses.
Bank accounts and personal assets had been frozen and a substantial amount of documentation had been seized.
Two other men arrested in Hull were released on Thursday. A 30-year-old was bailed until February and a 28-year-old has been detained by immigration officials.
Wednesday's arrests, under the Proceeds of Crime Act 2002, were the culmination of a complex year-long operation by Humberside Police's financial investigation unit.