He is the third person to be detained as part of the investigation.
A man has been arrested in connection with the alleged assault and false imprisonment of two men in Co.Louth earlier this month.
The incident is reported to have happened on Friday May 7th in Omeath.
This morning a man in his 30s was arrested and taken to Dundalk Garda Station for questioning.
He is the third person to be detained as part of the investigation.