Investigations are continuing following the discovery of a growhouse in Newtowncunningham.
Gardai carried out a search at a property in the Woodthorpe area last night at around 8pm.
Cannabis plants with an estimated value of €15,000, Cannabis Resin with a value of €1,000 and a small quantity of MDMA were seized.
A man in his 30s, was arrested and is currently being detained at Letterkenny Garda Station under Section 2 of the Drug Trafficking Act.
A technical examination of the scene is due to be carried out.