Smith & Nephew, the UK-based medical devices group, is considering clawing back some of the $889m it paid last year for its Swiss rival Plus Orthopedics after unearthing “unethical” sales practices by the company’s offices in several European countries led by Greece.

The group estimated it would lose $100m in annual sales as a result of stopping commercial tactics by Plus – believed to include kickbacks to purchasers – which it had not identified during due diligence.