DUP MP Ian Paisley has said he will refer himself to the Parliamentary Standards Commissioner over a report that he did not declare trips paid for by the Sri Lankan government.
The Daily Telegraph reported that the party founder's son accepted two holidays to the Indian Ocean island in 2013 for him and his family.
In response, Mr Paisley said: "The Daily Telegraph article is defamatory. It is devoid of fact or logic. Referred to my lawyer.
"I will refer myself to the Parliamentary Commissioner for Standards."
Mr Paisley is one of 10 pro-Brexit DUP MPs helping to prop-up Theresa May's Tory administration after her snap election left her with no overall majority.
He tweeted a picture this week of himself meeting the Sri Lankan High Commissioner Amari Wijewardene "to discuss NI-Sri Lanka trade deal after Brexit".
Two days later he tweeted a picture of himself with International Trade Secretary Liam Fox "discussing our trade agreements post Brexit".