NCIS detective Simon Goddard also took a swipe at those high street solicitors who fail to report their suspicions about clients.
He was angered by the latest NCIS figures which show the number of cases of suspicious financial transactions reported by solicitors to police has dropped from 300 in 1996 to 236 last year. There have been 210 disclosures so far this year.
"Why has it dropped when all the information NCIS is getting is that they are heavily involved?" said Goddard. "It's disappointing."
It compares to a total of 14,148 disclosures made by the financial sector, mostly by banks, building societies and bureaux de change.
Goddard said lawyers were either ignorant of their requirement by law to disclose suspicions, or deliberately turned a blind eye to potential wrong-doing when handling money.
He said: "The much wider group have suspicions that the money, or the transactions they are being asked to perform on behalf of their clients, is not right, yet they continue because there is a fat fee at the end of it.
He had this message for solicitors: "Lawyers have to examine their consciences and understand they have... a moral responsibility to ensure the rules and regulations are complied with."
The Home Office proposed to tighten laws on financial disclosures. Currently solicitors can only be prosecuted for not reporting clients they suspect of being involved in terrorism or drug trafficking. Under new proposals the net would include all crimes.