IT is inevitable and understandable that doctors will have close links to the pharmaceutical industry.

GPs and consultants rightly attend conferences to learn about new medicines, co-operate with drugs firms on research, and maintain a dialogue which, in most cases, serves the public.

However, doctors receiving money from Big Pharma is an issue that comes with a major health warning.

According to the industry's trade body, nearly £40 million was paid by pharmaceutical firms to doctors last year in consultancy and fees for attending meetings.

This means that some clinicians have multiple paymasters: the NHS, plus whichever drugs company has hired them.

The existence of NHS guidance from 2003 on such payments - which requires health boards to establish registers of interest - confirms the issue is of public interest, and needs oversight and transparency.

However, the fact that around 50% of NHS boards have failed to comply with the guidance for GPs is deeply concerning, as the public is in the dark about hundreds of doctors who may have financial links to the industry.

In a welcome move, the Scottish Government has ordered an investigation into this systemic failure, but stronger action should be taken.

Dr Peter Gordon, a consultant in the Forth Valley health board, has lodged a petition calling for legislation to require all healthcare workers to declare industry payments on a central register.

Simply hoping that NHS boards enforce existing guidance is a strategy that has failed for more than 10 years. A new law would be a better way of focusing minds on this important issue.