Four DUP politicians have made incomplete donation reports about a trip to Israel.
While Stormont Assembly Members Gary Middleton, William Humphrey, Michelle McIlveen and Jonathan Buckley reported donations to the legislature, they did not report them to the Electoral Commission within 30 days, the BBC reported.
The four-day visit in May was largely funded by the lobby group, Northern Ireland Friends of Israel.
It was intended to develop economic links in areas like cyber-security.
North Antrim MP Ian Paisley could face a by-election after he was suspended from Parliament for 30 sitting days over his failure to declare holidays to Sri Lanka.