He was arrested yesterday as part of an ongoing operation which saw six men rescued in Letterkenny last month.
On the 30th of August last Gardaí found five men in a business premises on Pearse Road in Letterkenny – they were safely removed and a sixth man located elsewhere in the town.
The six range in age from 21 to 45 and are now in secure accommodation.
As part of the continuing operation a man in his 40's was arrested in Letterkenny yesterday in connection with alleged people trafficking.
He's being detained under section four of the criminal justice act and can be held for up to 24 hours.
A number of bodies are involved in the investigation including Romanian Authorities and the Garda Human Trafficking Investigation and Co-ordination Unit.
Inquiries are continuing.
