New Zealand First MP Brendan Horan was not at Parliament on Tuesday after being told by party leader Winston Peters to sort out allegations relating to his late mother's finances.
Mr Peters earlier described the matter as a family dispute over a will.
He says Mr Horan's brother made a complaint to him in September this year about the MP, but has not sent him any information.
Mr Peters says the MP's No 1 priority is to sort the matter out and get the facts before him.
Mr Horan says he has not been sent on leave, but is following his leader's orders to clear things up.
The MP says he can't comment on the dispute as it is in the hands of his lawyers.