US company NMT Medical has threatened to step up its libel action against Dr Peter Wilmshurst, over comments he made last year on BBC Radio 4’s Today programme. The cardiologist is already being sued by the company for criticising its clinical trials of a device to treat migraines, at a medical conference in the USA in 2007. NMT has alleged that Wilmshurst’s most recent remarks suggested the company “sought to conceal his review”, and intends to take legal action on the grounds of defamation. It is not yet clear whether this will be a separate case or an addition to the existing libel suit.