Laing & Co told its retail brokers it was placing employers' liability (EL) cover with the Isle of Man insurer Ultra via Preston Whiteside.
Earlier this year, it was revealed that police were investigating brokers in Northern Ireland, Yorkshire and Scotland in relation to the fraudulent use of Ultra's name.
Retail broker Willis & Co paid EL and public liability premiums to Laing & Co on behalf of around 25 Northern Ireland clients.
In an affidavit filed with the High Court in Northern Ireland, Willis & Co director Peter Lennon said: "We received a facsimile from [Laing & Co managing director] Stuart Laing advising that, as far as liability after 1 August 2002 was concerned, this had been moved to another company called Ultra Insurance Co."
