NHS doctors who qualify overseas are more likely to face tough sanctions in disciplinary hearings, research has shown.

An analysis of General Medical Council hearings published in the British Medical Journal found doctors from abroad fare worse than those who qualified in the UK.

However, the study could not pinpoint the exact reasons for the differences, with experts saying it may be because overseas doctors are less competent and make more mistakes, or because GMC panels come down harder on them.

A separate study published in February found that NHS doctors who qualify overseas are twice as likely to generate concerns as UK graduates.

Some of the highest rates of worries are about non-white doctors who gain their medical qualifications overseas, who are also more likely to be suspended.

Among GPs, those who qualified outside Europe are almost four times as likely to generate concerns as those who graduate in the UK, and are six times more likely to be suspended.

Experts from the NHS-funded National Clinical Assessment Service analysed about 5,600 complaints over the last nine years, including 900 during 2009-10.

In the study, led by professor Charlotte Humphrey from King’s College London, experts found that GMC decisions about doctors who qualified outside the UK are more likely to have far reaching consequences.

They said perhaps “real differences exist in fitness to practise between groups of doctors who are referred to the GMC” or “the GMC processes tend to discriminate against certain groups of doctors”.

However, the authors said either conclusion may not be the right one and called for further research.