Vandals have caused £250,000 of damage to power lines supplying a Fermanagh business.
On Sunday there was a suspected arson attack at Quinn Tarmac in Ballyconnell, Co Cavan, and on Friday, power lines supplying Quinn Glass in Derrylin, in Fermanagh, were cut.
The PSNI and gardai are examining several positive motives.
They are conducting a joint investigation into the possibility of these attacks being connected.
There have been 14 similar attacks on power lines in Fermanagh over the last four months.
The decision by Anglo Irish Bank to remove Mr Quinn from his business empire and put a new management team in place sent shockwaves through the Irish business community.
The Quinn family owes the bank more than £2.55bn.
Sean Quinn, once Ireland's richest man, was removed from the company last April.