The DUP is to investigate claims MP Ian Paisley failed to declare another luxury holiday, this time to the Maldives, to parliamentary authorities.
A spokesman described the allegations levelled in a BBC NI Spotlight investigation as “very serious”, and said party officers would be considering them.
The programme raised questions over who paid for a holiday taken by the Paisley family in 2016.
Mr Paisley has denied the holiday was paid for by authorities in the Maldives, stating that he paid for part of the trip himself, while the rest was paid for by a long-term friend unconnected to his work.
He did not name the friend.
In a statement, the North Antrim MP added: “The Government of the Maldives did not organise or pay for my family vacation in 2016, which I do not intend to go into with you.
“I’m satisfied the vacation did not have to be recorded on the register.”
The allegations come just days after Mr Paisley returned to Parliament following a 30-day suspension for failing to declare two holidays paid for by the Sri Lankan government and lobbying on its behalf.
Sinn Féin leader Michelle O’Neill and SDLP leader Colum Eastwood have both called for Mr Paisley to resign – or for DUP leader Arlene Foster to remove him from the party.
“I think Ian Paisley should have resigned many months ago,” Ms O’Neill said.
“And I think where he finds himself again today at the centre of another scandal is not anything befitting of someone who holds public office.”
Mr Eastwood tweeted: “It really is time for Ian Paisley to resign. If he doesn’t, then the onus is on Arlene Foster to remove him from the DUP.”
Mr Eastwood has also written to the Parliamentary Commisioner for Standards asking her to investigate the allegations.
Another letter has been sent by UUP leader Robin Swann.
“There is an onus on Mr Paisley to cut the bluster and offer openness and transparency to the people of North Antrim,” he said.
“The allegations raised by Spotlight are extremely serious and deserve a credible response from Ian Paisley and the DUP.”
Mr Swann added: “The DUP also need to be open about when they learned of these allegations and what they know. They cannot simply hide behind a statement saying they will investigate.
“This is yet another stain on North Antrim and the reputation of politics in Northern Ireland.”
Mr Paisley has been MP for North Antrim since 2010.
Previously his father Ian Paisley Senior held the seat since 1970.