Truly innovative stem cell research is being suppressed by a clique of peer reviewers for high profile journals, several researchers claimed today.

They told the BBC that the problem lies with those responsible for producing the reviews of research that journals such as Nature use to decide whether to publish the work.

Two scientists told the BBC they believe that in some cases reviewers are submitting negative comments or demanding additional and unnecessary experiments to delay publication and allow their friends to publish first.

Austin Smith, a stem cell researcher at the University of Cambridge, says, “It’s hard to believe except you know it’s happened to you that papers have been held up for months and months by reviewers asking for experiments that are not fair or relevant.”

Last year Smith was one of 14 researchers to sign an open letter to journal editors warning that:

Papers that are scientifically flawed or comprise only modest technical increments often attract undue profile. At the same time publication of truly original findings may be delayed or rejected.

The letter authors want all reviews and editorial correspondence to be published along with papers.

Philip Campbell, Nature’s editor, says, “The idea that there’s some privileged clique is utterly false. Last year we used about 400 reviewers in stem cell and developmental biology, and we constantly recruit new referees.”

Monica Bradford, executive editor of Science, adds, “We do recognise that human factors such as competition and potential financial gains can bias a reviewer’s assessment of a paper and we expect our editors to consider these factors when evaluating the comments of the reviewers, particularly in cutting-edge areas of research.”