REUTERS/China Dail
Often people will take money abroad to do this, hoping that the cross-border aspect will make it harder to trace. A recent report from the UK government identified the top 10 countries British criminals turn to when they want to clean their cash, based on 5 years worth of criminal assets recovered from abroad.
The combined criminal assets recovered are worth over £600 million but the Treasury says: "The true figure will be significantly higher, as this figure only includes identified assets linked to offenders who have been convicted and had a confiscation order made against them. It does not take account of any assets linked to offenders who have escaped detection or conviction."
Check out the hot money hotspots below.