Mr Levine's men could be intimidating if they wanted to be. Among the guards on Primrose Hill are ex-soldiers from the Israeli, South African, Russian, Ukrainian and British military. Juan, 22, worked in security in South Africa before coming to the UK. He said: "Johannesburg is a very dangerous city. There are problems with gangs, violence and guns, so private security firms are common. It's sad that this sort of service is now needed in London."