Judgment has been reserved in former Health Minister Edwin Poots’ bid to overturn rulings which stated that his ban on gay men giving blood was irrational.
He is also challenging judicial verdicts that he breached the ministerial code and appeared to have been influenced by Christian beliefs in maintaining the lifetime prohibition.
Following extensive legal arguments in the Court of Appeal a panel of senior judges confirmed they wanted time to consider all submissions.
The legal battle over donations from men who have sex with men has continued for nearly four years.
The gay blood ban, put in place during the 1980s AIDS threat, was lifted in England, Scotland and Wales in November 2011.
It was replaced by new rules which allow blood from men whose last sexual contact with another man was more than a year ago.
But Mr Poots maintained the prohibition in Northern Ireland on the basis of ensuring public safety.
Findings were made against him in a judicial review sought by a homosexual man granted anonymity in the case and referred to as JR65.
A High Court judge held that the Democratic Unionist MLA did not have the power to keep the lifetime ban.
Challenges to the verdict have been continued by Mr Poots’ DUP ministerial successors and the British Health Secretary Jeremy Hunt.
Attorney General John Larkin QC, representing the Department of Health, argued that JR65 has no personal interest in the case because he was paid for sex.
Questioning the man’s legal standing in the case, Mr Larkin contended that he would be barred anyway because of the cash transaction and a further failure to comply with a 12-month celibacy rule.
Appeal judges were also told that Mr Poots was entitled to go against the rest of the UK on the issue, with devolved powers giving Stormont ministers the right to take a different view.
But counsel for JR65 claimed, based on evidence, that lifting the total ban would increase the risk of a contaminated donation getting through just once every 15,000 years.
According to their case Mr Poots’ acted irrationally in maintaining the prohibition because the threat was “infinitesimal”.
They argued that his decision was a “knee-jerk reaction” which went against the advice of his officials and experts.
The three judges, led by Lord Chief Justice Sir Declan Morgan, are expected to take some time to rule on the case.
Constitutional and EU law issues will also feature in their deliberations.