Doctors, researchers and patients are being undermined by a practice of “routinely and legally” withholding the results of clinical trials from them, a group of British politicians says.

In a report released today on the United Kingdom’s stockpiling of the drug Tamiflu, used to treat influenza during a pandemic, the Committee of Public Accounts of the House of Commons has weighed in to the debate over access to clinical-trial data. The United Kingdom has spent £424 million (US$697 million) in recent years stockpiling Tamiflu, but had to write off £74 million of this, as it was not clear the medicine had been stored correctly.

A vocal group of medical researchers has questioned the evidence base for Tamiflu, in part because they say that many details of trials of the drug have not been released by its manufacturer, Roche, which is headquartered in Basel, Switzerland. Their campaign has been spearheaded by the Cochrane Collaboration, which is a group of medical researchers, and the British Medical Journal.

Richard Bacon, a member of the committee, said in a statement that the committee was “disturbed by claims that regulators do not have access to all the available information”. He also said that a “lack of transparency of clinical-trial information on this drug to the wider research community” is hindering proper assessment of Tamiflu’s efficacy.

“The ability of doctors, researchers and patients to make informed decisions about treatments is being undermined,” says Bacon.

The report from comes just days after an industry scheme to share data from clinical trials came into force, backed by the European Federation of Pharmaceutical Industries and Associations (EFPIA) and the US Pharmaceutical Research and Manufacturers of America (PhRMA). The European Medicines Agency (EMA), the regulator for drugs in the European Union, is also pushing forward with plans to make more clinical-trial data available.

However, the new report says these moves are inadequate, as they do not address access to data from all trials, and, in particular, they do not apply to those from previous years.

In its response to the report, Roche said that its own policies on data sharing go beyond the EFPIA and PhRMA guidelines.

“We support the call for greater transparency in access to clinical-trial results. This is why we expanded our policy last year to provide enhanced access to data from our clinical trials,” read the statement.

The company says that it has already sent the Cochrane Collaboration all 77 of the studies it sponsored on Tamiflu, in line with its policy, which came into force last year.

On the other side of the arguments, Ben Goldacre, the co-founder of the AllTrials campaign for greater openness of clinical-trial data, called the report “a complete vindication” of the campaign.

“Industry has claimed it is on the verge of delivering transparency for over two decades,” he said in a statement. “While obfuscating and delaying, ever more results have been withheld.”