There have been calls for increased transparency regarding political donations after Stormont's parties denied being the subject of an investigation by the Electoral Commission.
The commission investigated two separated political donations, however it cannot legally disclose any details about the probes as only information on donations made after July 2017 can be made public.
Historically, donations to Northern Ireland's political parties have been kept private for security reasons.
The subject of one of the two investigations is the Alliance Party MLA Andrew Muir, the party confirmed to the BBC.
Mr Muir failed to declare a trip paid for by the US Government during his time as a representative on Ards and North Down Borough Council.
The North Down MLA said he declared the trip to the council at the time, however he was unaware it also had to be declared to the Electoral Commission.
"He rectified that as soon as it was made clear and apologised for his lateness," the party said.
"The commission made no determination of an offence in this case. Openness and transparency is of the utmost importance to Alliance, illustrated by the party leading on declaring political donations."
The other Electoral Commission investigation remains shrouded in mystery, as Sinn Fein, the DUP, Ulster Unionists, SDLP, TUV, Greens and People before Profit all denied involvement.
It is possible, however, that other parties not currently holding any seats in the Assembly could be the subject of the investigation.
SDLP leader Colum Eastwood said scenario highlights the need for further transparency regarding political donations.
"This does not add up, there was an investigation and clearly some party must be aware of it," he said.
"This reinforces the need for the full details of Electoral Commission investigations to be published if the public are to have any confidence in the political system."
The Electoral Commission said it will continue to push for legislation to be passed to allow more details of donations to be made public.
"We regret that we are unable to disclose information about donations prior to 1 July 2017," Electoral Commission director of regulation Louise Edwards said.
"We continue to urge the UK government to bring forward legislation that will enable us to publish information on donations from January 2014.
"This would give transparency and confidence to voters in Northern Ireland."