The DUP leader's lobbyist son was part of a Stormont delegation representing one of the north's largest social enterprises.
Bryson Charitable Group has insisted that it did not procure Gareth Robinson's lobbying services. However, the Irish News can reveal that a director of its subsidiary Bryson Energy took part in a series of meetings at Parliament Buildings last year involving the First Minister Peter Robinson's son.
The meeting sought to influence party policy on the Warm Homes scheme, an energy saving initiative funded by the Department for Social Development (DSD).
Present alongside Gareth Robinson representing Bryson Energy were the company's director Nigel Brady and fellow lobbyist Terry McErlane of Resolute Public Affairs.
Earlier this month The Irish News revealed how the DUP leader's lobbyist son regularly brings his clients to Stormont for meetings with ministers, MLAs and party officials.
One Stormont insider claimed Gareth Robinson had a DUP pass which allowed him "access all areas" at Parliament Buildings – a privilege normally reserved for assembly members, party workers and staff.
John Dallat, the SDLP vice chairman of Stormont's public accounts committee, said a corresponding scenario in which a close relative David Cameron's was working as a lobbyist at Westminster "would not be tolerated for a second".
Recent guidance issued to assembly members by Stormont's Standards and Privileges Committee says members must register "any interests they have arising out of their interactions with lobbyists", however, the latest records indicate that to date no MLAs have made such a declaration.
Bryson Charitable Group, said in a statement, that it never "sought to procure, or been invited to procure, the services of Gareth Robinson".
"Gareth Robinson has never facilitated or arranged any meeting(s) whatever for or on behalf of Bryson Charitable Group and Mr Robinson has never been invited to accompany any employee(s) or representative of Bryson Charitable Group to any meeting(s) in Stormont," the statement said.
Mr McErlane, who formerly worked at PR firm Weber-Shandwick, said: "Gareth Robinson was one of a number of consultants who provided strategic communications advice to Resolute Public Affairs when it worked for Bryson Energy.
"At no time did he arrange or was he asked to arrange meetings at Stormont."
Last night Mr Dallat said recent revelations highlighted the need for assembly to tighten the rules around lobbying.
"Stormont needs to draw a clear line between what is lobbying and what exerting influence is," the East Derry MLA said.
"Revelations about the first minister's lobbyist son having free access to Parliament Buildings only undermine the image of the devolved institutions at a time when they are in a particularly perilous situation."
A spokesman for DSD said that "to the best of our knowledge" no social development minister or DSD official had met or corresponded with Gareth Robinson or any representative of his Verbatim Communications company in the past 12 months.
Gareth Robinson's Verbatim company came to prominence last year when the Irish News revealed that the DUP leader's son had been employed by Barry McGuigan's Cyclone Promotions in an unspecified role.
Cyclone Promotions' sell-out Titanic Showdown bout between Carl Frampton and Kiko Martínez received £300,000 of public money. The promoter also had most of the £35,000 policing bill for the event waived.
In the run-up to the fight, First Minister Peter Robinson asked the head of the civil service Malcolm McKibbin to explore funding opportunities for the event.
