The experts are supposed to represent patients and provide independent advice and guidance to the US’s drug regulator, the Food and Drug Administration (FDA)—but many are receiving payments from the manufacturer, and sometimes they are keeping the connection secret.

More than 90 per cent of the experts spoke positively about a cancer drug in 49 of the FDA advisory committee meetings held between 2009 and 2014. Although 30 per cent admitted having financial ties, others hid the fact, and were discovered only when researchers from the Oregon Health & Science University carried out web searches.

Commenting on the findings, lead researcher Vinay Prasad, a specialist in blood cancers, said: “The industry has hijacked that microphone”, referring to the advisory meetings.