DUP MP Ian Paisley has been queried over his use of a royal emblem in party political advertising.
The North Antrim MP had several advertisements placed in local newspapers this week which included the House of Commons badge, the Crowned Portcullis.
Parliamentary rules tightly restrict how MPs can use the badge and any issues can be investigated by the standards commissioner.
The emblem is authorised to the House of Commons by licence granted by the Queen.
The UK Parliament website says the Crowned Portcullis "should not be used for purposes to which such authentication is inappropriate".
Such emblems should also not be used "where there is a risk that their use might wrongly be regarded, or represented, as having the authority of the House".
An MP committee report in 2019 said the emblem may be used by members "on their stationery provided by the House or used for their parliamentary functions".
It added the Crowned Portcullis must not be used in an "inappropriate form".
Mr Paisley's advertisements, which were published in two newspapers in his local area, included the DUP logo and an image of the MP.
The adverts gave welfare payment figures in a bid to promote how Mr Paisley's constituency office had assisted members of the public.
Mr Paisley is quoted in one of the ads saying, "I have a reputation for fighting for constituents' needs and getting the job done."
A House of Commons spokesman said it was unable to comment on individual instances of the use of the Crowned Portcullis.
He added: "If the Crowned Portcullis has been misused, it would be a matter for the Commissioner for Standards."
The DUP was asked whether Mr Paisley had sought permission to use the Crowned Portcullis in these advertisements.
The party was also asked whether they regarded the use of the emblem to be within parliamentary rules.
The DUP did not respond to requests for a comment.
