Airport donated £4,000 to Ian Paisley's constituency association
Belfast International Airport donated £4,000 to the DUP in North Antrim this year, a watchdog has said.
The money was paid to the party's North Antrim Westminster Association. Ian Paisley is MP for the area.
This is the second time the Electoral Commission has published such information after legislation was passed at Westminster to allow donations and loans worth more than £7,500 to parties in Northern Ireland to be listed.
Another donation worth £2,000 was paid by former party candidate James Kingan to the UUP's North Down Association.
Ann Watt, head of the Electoral Commission in Northern Ireland, said: "We welcome the public scrutiny and transparency this allows within our democratic process."
A statement from Belfast International Airport said: "We support all our political parties where it is clear that the events they organise are to the benefit of the airport.
"We are currently campaigning for the removal of air passenger duty and that means engaging with senior government figures to get our points across.
"We will continue with our efforts to remove APD and to engage with all politicians from whatever party to achieve that objective."
The total accepted in the first quarter of this year included £107,848 to the DUP and £80,327 to Sinn Féin.
Ms Watt said it was "disappointing" to report that two parties failed to deliver their returns on time - Sinn Féin and the United Kingdom Veterans' and People's Party.
"Where there is no reasonable explanation for such a failure we will take a robust approach in line with our enforcement policy."
Meanwhile, the commission is investigating money paid by a local council in Northern Ireland to sponsor a table at a DUP dinner.
A donation of £1,500 is at the centre of the probe into an event hosted by Mr Paisley at the Tullyglass Hotel in Ballymena, Co Antrim, last year.
Environment Secretary Michael Gove was guest speaker.
A commission spokesman said: "The Electoral Commission has opened an investigation into the donation from Mid and East Antrim Council to Ian Paisley MP.
"We can't go into further detail as this is now a live investigation."
Mr Paisley has said the council's money went directly to the hotel.
He said: "I can confirm the Electoral Commission is continuing its investigation into Mid & East Antrim Borough Council's purchase of a table at my constituency dinner last year.
"I look forward to them concluding the matter soon."
The DUP is propping up Theresa May's minority government at Westminster on key votes and has hosted Conservatives a number of times in Northern Ireland.
The council has said the money was paid to Tullyglass Hotel and not to the DUP.
Under Electoral Commission rules, councils are not considered permissible donors, meaning any money should be returned.
A council statement said: "Council received an invitation to a North Antrim Annual Business and Community dinner at the Tullyglass Hotel, hosted and facilitated by Ian Paisley MP, with special guest Rt Hon Michael Gove, sponsored by Belfast International Airport.
"Council paid the Tullyglass Hotel via electronic payment.
"No money was exchanged between council and the DUP. Council will fully co-operate with any investigation."