A man in his 30's who was questioned about the abduction of Quinn Industrial Holdings director, Kevin Lunney, has been released without charge.
Three other people - two men, aged 23 and 61, and a 61-year-old woman - who were arrested in Fermanagh as part of the investigation were released without charge yesterday.
Gardai say a file is being prepared for the Director of Public Prosecutions.
Mr. Lunney was kidnapped and brutally assaulted by a group of masked men last September.
The attack was the most serious act in a campaign of intimidation against executives at QIH that has been ongoing for several years.
Anyone with any information about the abduction is being asked to contact Cavan Garda Station on 049-436-8800, the Garda Confidential Line on 1800-666-111, Crimestoppers on 1800-25-00-25 or any Garda station.