In March, parliament’s foreign affairs committee asked me to come and tell them what to do about dirty Russian cash. “If any dirty money is invested in UK property, it was before 2008; or before 2011 at the latest, not now. His conclusion was that too many influential people – lawyers, bankers, accountants, property developers – were dependent on dirty Russian money for their livelihoods. This is one of the problems with trying to ascertain the volume of dirty Russian money in London: how far back do we go? Does the commission the estate agent earned by selling those flats in Kensington in the early 1990s count as dirty money?