The European Court of Human Rights said Thursday that French authorities had violated the privacy of a would-be blood donor by labelling him a homosexual before laws were changed to allow gay men to donate.

The issue has long been controversial in France, where hundreds of people died in the 1980s after the national blood transfusion centre distributed HIV-tainted blood.

Blood donations by gay and bisexual men were outlawed from 1983 to 2016 when France lifted the ban but still required them to affirm sexual abstinence for a year before giving blood.

That rule was fully lifted last March.

In 2004, a Parisian man, Laurent Drelon, attempted to give blood with the country's EFS national blood transfusion agency, but refused to answer when asked during a screening interview if he had had sexual relations with another man.

That led the EFS to mark him as a homosexual in his donor file, effectively excluding him from attempting to donate again in 2006.

Drelon then filed unsuccessful discrimination complaints.

He was again prevented from trying to donate in 2016, when he filed his application with the European rights court, based in Strasbourg, eastern France.

"The court found that the collection and retention of sensitive personal data constituted an interference with the applicant's right to respect for his private life," it said in a statement.

The personal data was based on "mere speculation," the court ruled, adding it had been kept for an "excessive retention period" that was not justified by the aim of preventing gay men from donating blood.

The judges ordered France to pay Drelon €3,000 in damages as well as €9,000 for legal costs and expenses.

His case was one of several challenges to the French ban on donations by homosexual men before the law was changed under pressure from gay rights groups.

According to studies, the opening up of blood donations to gay donors has not increased the risk of HIV transmission via blood transfusions.