The 26-year-old won five England Under-21 caps but qualifies to play for Northern Ireland through his grandfather.
He made the switch to Nigel Worthington's team by featuring in their recent Euro 2012 qualifiers against Serbia and Slovenia.
Camp insists his change of allegiance had nothing to do with being denied a call-up to the senior England squad by Fabio Capello.
"There were stories about me being annoyed at not getting an England call but nothing could be further from the truth," he told The Sun. "It was probably someone being a bit mischievous.
"Playing for Northern Ireland is a real feather in my cap - I should have done it earlier."