The Sunday Tribune is to pursue legal action in response to the Irish Mail on Sunday's publication yesterday of thousands of newspapers featuring a mocked-up Tribune masthead.
The Mail has been widely criticised for the move, which came as publication of the Tribune was halted due to the appointment of a receiver to the title, putting 43 jobs under threat.
Described by the Mail as a "marketing exercise", the move saw around 25,000 'special editions' of the Mail being distributed to news outlets mainly in the east of the country yesterday.
The move attracted widespread criticism with Tribune editor Noirín Hegarty describing it as "shameless".
The National Consumer Agency (NCA) this morning confirmed it is also considering prosecuting the Mail for a breach of the Consumer Protection Act.
Ms Hegarty said there may also be issues in relation to the Press Ombudsman and the National Newspapers of Ireland, and that legal action is being pursued.
"This was an appalling trick that was played on consumers and on newspaper readers," she said today.
"We are taking legal action… as we believe it was a breach of copyright.
"Our legal team has been on to this since yesterday morning under the direction of the receiver Jim Looby."