A whistle-blower in the Pfizer healthcare fraud scandal has said he felt he was "swimming upstream" when the firm was illegally promoting drugs.
"It's hard to do what's right when everyone else around you is following management sales directive," John Kopchinski told the BBC's World Today.
Mr Kopchinski was awarded $50m (£31m) for helping expose Pfizer's wrongdoing.
Pfizer is paying $2.3bn after promoting four drugs for conditions different to those for which they were approved.
Ray Kerins, a spokesman for Pfizer, said the company had a strong commitment to compliance transparency.
