A large dumper truck was abandoned across the entrance to the Co Fermanagh headquarters of the Quinn Group today.
The vehicle prevented cars from going in or out of the Derrylin business after it was driven into bollards in front of the property.
It follows the decision by Anglo Irish Bank to remove founder Sean Quinn from the company last week.
A Police Service of Northern Ireland (PSNI) spokeswoman confirmed: "Police in Enniskillen are investigating criminal damage caused to the front of commercial premises in Derrylin.
"At 12.30am a large earth-moving vehicle has been driven into bollards at the front of the property and abandoned, causing damage to the bollards."
Mr Quinn's family owes the bank €2.8bn but some people in the border region remain loyal to him, praising him for creating jobs in the area.
Last Thursday, Anglo Irish Bank appointed accountants KPMG to take control of the Quinn family shares in the business.
The bank`s chief executive Mike Aynsley said it was owed an enormous amount of money by the Quinns, which they were not in a position to repay.
Employees have been told that there are no plans for any job losses.
Lobby group Concerned Irish Businesses (CIB), which represents 550 Irish companies, criticised the actions of those responsible for parking the truck but said solidarity with Mr Quinn should be shown through peaceful means.
A spokesman said: "Quinn Group was built by Sean Quinn over a period of 37 years, and during that time personal relationships were built with customers, suppliers and staff alike.
"Those relationships were broken as of last Thursday, a day when over 90,000 signatures who had pledged their support for Sean Quinn were handed into relevant authorities. However, those in authority failed to recognise these people, and their wishes."