The UK's Serious Fraud Office has just announced two formal investigations into Rio Tinto and British American Tobacco. But why now? \n \nAnnouncing probes into huge companies like these seems to show that the SFO is still trying to prove its worth (both to Theresa May and the wider public) after it was proposed that it should be subsumed into the UK\u2019s police body, the National Crime Agency.\n\nListen in as MLex anti-bribery and corruption correspondents Martin Coyle and Ben Lucas talk with London News Editor Ben O'Neill about the agency.