"Who makes this s**t up?", Marshall said on last night's NRL 360. "I think I shared with a couple of people, a couple of years ago, I might have thrown a porkie out and said I was Scottish and I could play for Scotland - as a gee up. And they obviously believed it. But I'm not even eligible to play for Scotland.
Despite, Marshall falling out of favour with the Kiwis following his brief rugby stint with the Blues last season, he says he attended a recent meeting of New Zealand players and is fully committed to the Kiwis.
"It's bulls**t. I have no interest to play for Scotland at all," Marshall told the Sydney Morning Herald.
"I'm fully committed to playing for New Zealand. I went to the last meeting of New Zealand squad members six weeks ago, everything between me and Stephen Kearney is fine and I am in line for the end of season tour."
Coach Stephen Kearney has opted for the younger halves combination of Shaun Johnson and Kieran Foran which has resulted in a Four Nations title and an Anzac test victory in the last eight months.