In September 2003, a secret transaction took place. The location was Monaco, a tax haven associated with the international rich. Specifically, an exclusive block just beneath its lavish casino. An apartment changed hands. A local notary signed the deal. Purchase price: €3.6m (£3.1m). For this, the buyer got a luxury fourth-floor flat, two parking spaces, a storeroom, and the use of a pool in the Monte Carlo Star complex.
From the balcony the new owner could gaze down on Monaco’s sparkling marina, stuffed during the summer with floating superyachts. Security ensured residents were undisturbed by tourists milling around a mini-garden built on the complex’s roof. There were sounds, too, pleasant ones – the clatter of helicopters ferrying new arrivals from Nice airport, and the screeching of swifts.