London has long been a destination of choice for wealthy families looking to relocate or simply to invest in prime real estate. In recent months however the mood has changed. In January 2018 the government introduced the unexplained wealth order or UWO. This so-called ‘McMafia Law’ introduces a powerful tool to compel individuals to provide information about the source of their wealth.

The first ever UWO was obtained in February 2018. Shortly thereafter we were instructed in challenging that order. The case led to a media frenzy with tabloids and broadsheets alike enjoying poring over the details of one lady’s spending in H...