When Lanny Breuer, the head of the criminal division of the US Department of Justice, warned a conference of pharmaceutical industry lawyers last year that prosecutors were gearing up for an investigation of international corruption in the sector, the drugs companies took notice.

Mr Breuer's threat has now become a reality. A host of big pharmaceutical companies – Merck, AstraZeneca, Eli Lilly, Baxter, SciClone, and Bristol-Myers Squibb – have in recent months received inquiries from the Department of Justice and the Securities and Exchange Commission in connection with an industry-wide bribery -investigation.

GlaxoSmithKline, the UK drugmaker, told the Financial Times yesterday that it too had received “inquiries” from US authorities, but that it disclosed the issue “reactively” only to selected reporters in April.