DUP social development minister Maurice Morrow has also claimed St Patrick was a Protestant, it has emerged.
His comments were highlighted after high-profile unionist Ruth Patterson claimed on Wednesday that St Patrick was a "former Protestant".
The claim raised eyebrows as critics pointed out that St Patrick lived around 1,000 years before the Protestant Reformation.
But it has also sparked discussion among senior religious figures about Ireland's patron saint.
Retired Free Presbyterian minister Rev David McIlveen, a close friend of the late Ian Paisley, said St Patrick would have ascribed to "biblical Protestantism" if alive today.
But the Church of Ireland's Henry Hull, Dean of Down, said it's "erroneous to describe Patrick as either a Protestant or a Roman Catholic".
Lord Morrow's comments were made last year on BBC Radio Foyle while debating with Sinn Féin's Phil Flanagan on calls for Stormont to be illuminated green for St Patrick's Day.
The DUP Fermanagh and South Tyrone MLA said: "It should be remembered that St Patrick was in fact a Protestant, and St Patrick is someone whom I have considerable regard and respect for, and I wouldn't want him to be used then as some sort of a political football."
Mr Flanagan responded: "Maurice Morrow's hanging about England too much. He needs to actually catch himself on, running about telling people that St Patrick was a Protestant.
"As far as I remember when I was taught at school there was no such thing as a Protestant religion in 432."
Mr Flanagan shared on Twitter a recording of the comments following Belfast councillor Ms Patterson's remarks on BBC Radio Ulster.
Last week Lord Morrow was appointed social development minister after DUP colleague Mervyn Storey moved to the Department of Finance.
Amid the controversy Rev McIlveen yesterday said he believes St Patrick would today identify with "biblical Protestantism" rather than Roman Catholicism.
"The Reformation message was based upon the bible so in that sense I can understand how people will almost transfer the name of 'Protestant' to St Patrick, because that's one way of describing him in terms of his beliefs," he said.
The Church of Ireland's Very Revd Henry Hull said St Patrick brought the message of Christianity to Ireland for everyone.
"It is erroneous to describe Patrick as either a Protestant or a Roman Catholic because Patrick lived at a time when today's divisions did not exist," he said.
"Patrick brought the message of Christianity to Ireland and Christians of all traditions look back to that time. Therefore Patrick serves both as an inspiration as someone who shared the good news about Jesus, and as a reminder of the common faith shared by all Christians."
A DUP spokesman said: "Should Phil Flanagan decide not to branch out in future as an expert in social media he could instead offer his services in theology. Discussions on the interpretations of Patrick's teaching are an interesting exercise, but of limited political interest."
