Many local residents around Dundalk have been comlaining for the past number of days about the smell in the area.
However, according to local Louth County councillor Maeve Yore, the reason for the stench has been revealed.
"For those of you who still have a sense of smell around Long Avenue, Red Barns Rd, Rock Rd, Quay St area Chicken 'Poop' fertiliser is being spread !' she wrote on Facebook.
'I have checked with Council and compliance section LCC have advised all licences/permits been adhered too - smell should subside by 6pm tonight,' she added.
With the good weather having arrived this week, the smell was even worse than could have been expected.
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