Three London homes worth more than £80m have been frozen by the High Court in the second-ever use of anti-corruption orders to stop foreigners laundering cash in the UK.
The National Crime Agency has demanded that the subject of the probe explains the source of their wealth.
The Unexplained Wealth Orders (UWOs) were sought last week against a foreign official who was not named in court.
The homes cannot be sold or given a new owner until the investigation is over.
The properties are held by offshore companies.
UWOs are a new anti-financial crime power targeted at foreign government officials and their families from outside the European Economic Area (EEA) who are believed to have laundered stolen money through British property.
If the suspect – known as a “politically exposed person” – cannot explain the source of the wealth, the NCA can ask the High Court to order the homes’ seizure.
The measure aims to target people who have committed huge frauds and embezzlements abroad where there is little or no chance of obtaining the evidence to convict them in a British court.
The first ever UWO was used against Zamira Hajiyeva, the wife of a jailed Azerbaijan banker, who lives in a £12m London home and owns a Berkshire golf course.