The man, 36, was arrested after a tip-off from a female worshipper at the church, a church member told TV3 moments after the incident.
Confirming the incident on Sunday in a statement, the Minister of Communications, Dr Edward Kofi Omane Boamah, said the man was arrested “after his fidgety and suspicious behavior was noted during the morning service”.
He announced that “National Security investigations are ongoing”.
It is unclear what motive the man might have had in carrying a weapon to a church but most church members denied knowing him as a member.
Dr Boamah said that President Mahama and his family were not at church when the incident occurred but TV3’s sources said his children had been driven there by his official driver.
Aside the president, the head of the country’s judiciary, Chief Justice Theordora Wood, also fellowships at the church.