You might be thinking of United Christian Broadcasters who used 549 and 6200 from transmitters in Ireland, think the same site? Was unlicenced. At one point they broadcast from the Kaliningrad Russia transmitter on 1386 evenings, there's another report I found saying they'd been granted longwave and mediumwave frequencies by Russia. That would be late 1990's onwards IIRC.

Spirit Radio's medium wave frequency had an audience in Northern Ireland, used to be complaints from them online when 549 was off the air.