Gardai are investigating if the savage abduction and assault of Kevin Lunney was masterminded by a criminal to set up Sean Quinn.
Senior Garda sources confirmed that the development is "one line of inquiry" that they want to "bottom out" in what detectives expect to be a prolonged and complex investigation.
Gardai believe they have identified the gang which abducted Mr Lunney, slashed him, beat him and doused him in bleach, as criminals based in Cavan and the Midlands - but not the suspected mastermind.
A Garda source said they are looking at a number of suspects including a well-known criminal who may have ordered the attack because of a grudge against former billionaire Mr Quinn. But Quinn Industrial Holdings (QIH) director John McCartin dismissed the theory.
"The whole concept has no thread of logic to it. It sounds fanciful and I would fear that it would detract from the central focus of the investigation and could lead to muddying of the waters in the investigation," he said.
Gardai say the attack on Mr Lunney did not fit the modus operandi of any of the previous attacks waged against QIH directors and businesses. The scale of the brutality was a marked escalation compared with previous attacks; there was no warning of the attack or heightened tensions in advance of it.
However, an anonymous letter was sent to the company and a solicitor in May warning the directors of a "permanent solution" for one of the five Quinn directors. A similar threat was conveyed to Mr Lunney by the criminals who savagely assaulted him.