THE southern-manfactured Tayto crisps at the centre of a court action against their sale in Northern Ireland had been available at the Bar Library in Belfast.
It emerges after Tayto NI issued trademark infringement proceedings against a sole trader for selling the Republic's Tayto crisps brand north of the border.
The southern variety of Tayto was among the foodstuffs provided to the Bar Library by the Dublin-based hospitality firm Baxter Storey.
A source said it is understood the business recently removed all Tayto products after it "got wind of the case going to court" against Ballynahinch man Mark Ferris.
Mr Ferris accepted breaching Tayto NI's trademark by selling the southern-manufactured brand of Tayto to shops and pubs in Northern Ireland.
But the 48-year-old said he feels "victimised".
A Northern Ireland Assembly spokeswoman refused to say whether southern Tayto has been available at Stormont, saying only that catering is through an external provider.
Read More: The question remains: which Tayto tastes best?
Translink said its Enterprise rail service on-board catering is operated by an external contractor based in the Republic which sells "products from suppliers in northern and southern Ireland, including Tayto crisps".
Baxter Storey did not respond to requests for a comment.
Meanwhile, a solicitor who advises on intellectual property said the legal case affirms that "both Tayto entities are separate brands operating in distinct territories".
Paul Lenehan, a partner in Belfast-based law firm Edwards & Co, said the same legal issues are likely to impact any traders trying to sell northern Tayto in the Republic.
"I think the true impact of the judgment will centre around the case acting as a stark reminder that Tayto (NI) is prepared to litigate against those who seek to infringe its intellectual property rights in cases such as this," he said.
