Britain's leading medicines watchdog is to investigate claims made by a senior doctor of 'unethical behaviour' by a major pharmaceutical company over a study of a disease that affects millions of women.

A series of emails and taped telephone conversations passed to The Observer reveal that a highly respected academic in the field of osteoporosis has questioned Procter and Gamble's decision to publish drug research in his name even though he had not been given full access to the data it was based on. The report was written by a 'ghost writer' paid for by P&G before being given to the academic to agree.

The claims made by Dr Aubrey Blumsohn, senior lecturer and bone metabolism specialist at Sheffield University, are to be looked at by the Medicines and Healthcare Regulatory Authority.

The issue will also be debated by MPs this week when the Commons meets to discuss whether the regulation of the pharmaceutical industry should be strengthened.

Blumsohn has told The Observer that he became highly concerned about the analysis of data collected as part of a study he was conducting on drugs manufactured by Procter and Gamble. The research was into the effect the osteoporosis drug Actonel had on women at risk of fractures.

Blumsohn claims that for nearly a year he was prevented from seeing the full data, despite being named as the lead author on the study, and having two reports published in his name. Two years after raising his concerns about research conduct, he was suspended from his university post after he threatened to speak to medical journalists about the issue.

Procter and Gamble strongly denies his claims, and says that that it is 'standard industry practice' not to hand over all data to academics.

It argues that it gave him as much access as possible to the information that formed the basis for papers and conference posters about the effects of the drug. But emails and taped telephone conversations reveal that, for nine months between 2002 and 2003, Blumsohn had to fight to be allowed to see the data. The company told him that the ghost writer, Mary Royer, was familiar with the 'key messages' they wanted to convey about the drug.

Actonel earns Procter and Gamble around $1 billion a year, and is very widely prescribed for women with osteoporosis, a bone condition that leaves them at risk of fractures. It is known to be a safe and effective drug, and the issues raised by Blumsohn do not suggest otherwise. It is competing against a rival osteoporosis drug, Fosamax, made by Merck.

There are increasing concerns among medical ethicists about the relationship between the major drugs companies and the academic institutions that are paid millions of pounds each year to carry out research on their behalf.

Pharmaceutical companies gain more credibility for their studies if they bear the name of independent academics holding university posts even if they haven't actually written the report.

In many cases, the work is carried out in a university laboratory and then sent off to the company for further work. However, researchers are supposed to have full and independent access to the data. This is particularly the case if it ends up being published in a medical journal.

The MHRA will hold an initial inquiry into Blumsohn's allegations by looking at the documentary evidence. They can go further and hold a full inquiry if they decide that there is a case to answer. A spokesman said last night: 'An allegation has been made and the MHRA is investigating.'

A Commons debate will be held on Thursday on the regulation of the pharmaceutical industry. The Liberal Democrat MP, Paul Burstow, who sits on the health select committee, said: 'It is essential that universities feel confident that they can defend their academics and that they get the access to data which they need before they can give it their stamp of approval.'