The US Department of Health and Human Services is to look again at the lifetime blood donation ban for men who have had gay sex.

The department said yesterday that the current policy is “sub-optimal” and announced it has instructed advisors to study whether the strict rules can be relaxed.

A statement said: “If the data indicate that a change is possible while protecting the blood supply, we will consider a change to the policy.”

Currently any man who has had sex with another man since 1977 is permanently barred from donating blood. The policy began after fears that allowing gay and bisexual men to donate blood could raise the risk of HIV and hepatitis for blood transfusion patients.

Although all blood is tested before use, there is a small risk that new HIV infections may not be picked up. Gay rights groups and the Red Cross say that donor screening should be based on risky behaviour, rather than a blanket ban based of sexual orientation.

The HHS is to consider risk factors in current donors, how blood can be accidentally released without safety clearance, whether potential donors would comply with new rules and whether new screening criteria would assure blood safety.

The department added: “It is anticipated that the described studies will yield data for reevaluation of the current deferral policy and potentially establish safety of blood collection from a subset of men who have sex with men or other currently deferred donors.”

Senator John Kerry has been pushing for a change to the policy.

He said: “We’ve been working on this a long time in a serious way and I’m glad Secretary [Kathleen] Sebelius responded with concrete steps to finally remove this policy from the books

“HHS is doing their due diligence and we plan to stay focused on the end game – a safe blood supply and an end to this discriminatory ban.”

The UK has a similar ban, which is under review.

SaBTO, the advisory committee on the safety of blood, tissues, and organs, is expected to report its findings at some point this year.