Sinn Féin TD Thomas Gould has said he's "entirely innocent" after being questioned by Gardaí investigating an alleged business fraud over a decade ago.

In a statement issued through a solicitor in Cork overnight, Deputy Gould confirmed he was the Oireachtas member questioned on Friday and later released without charge.

He has said he's shocked and angry over the complaint made against him by "a former employer" and "confident he will be vindicated".

Sinn Féin leader Mary Lou McDonald said he informed the party last month that a complaint had been made against him, which he "emphatically denies".