The study published last October linking the XMRV virus with chronic fatigue syndrome was as dramatic as they get in medical science. Researchers found the virus in two thirds of a cohort of patients with the debilitating illness – striking support for a cause and effect.

The announcement was backed up by a scientific paper that had passed muster with the peer-review process of science – it had been deemed fit enough by a team of independent experts to be published in the journal Science.

Now another research group has failed to replicate the findings and three or four other teams are also believed to be having difficulty supporting the original results. There does not seem to be a clear link, if any, between XMRV and chronic fatigue syndrome, which affects some 250,000 people in Britain.

Peer review and the independent replication of results are both critical to the scientific process. Without them, it would be impossible to sort the wheat from the chaff. And the October study appears to have failed the all-important test of replication.

It is now incumbent on the scientists involved to share their resources to establish why. Science should also publish any further studies that can answer whether or not XMRV is a genuine cause of chronic fatigue syndrome.