Stourbridge MP Cat Eccles is being investigated by the parliamentary standards watchdog over claims that she was late declaring a trip to Israel and Palestine.
The standards commissioner, Daniel Greenberg, announced that he was looking into a possible breach under rules about the declaration of an interest and the late registration of an interest.
In the most recent filings, Eccles listed a trip to Israel and Palestine, sponsored by Labour Friends of Israel, with flights, accommodation and meals totalling £2,600.
Ms Eccles has been contacted for a comment.
Parliamentary rules state MPs must “always be open and frank in declaring any relevant interest” and register such interests within 28 days.
The trip was listed as having taken place between 25 and 29 May but was registered with officials on 9 July.
The purpose of the visit was described as being for meetings with politicians, academics, activists and diplomats.
The Express and Star reported on Saturday that a spokesperson for the MP said missing the deadline was due to an administrative error and there had not been any attempt to conceal the trip.