A Cairns woman has received a personal apology from a senior Queensland officer after she was arrested over a 20-year-old parking fine.

Queensland police have admitted they acted outside their authority when arresting a Cairns woman over an outstanding parking fine from 20 years ago.

The 57-year-old was arrested on July 18 by officers who were acting on a Warrant of Execution issued in 1994.

The woman was not lodged into the local watch house.

Legislative change was initially blamed for the error, however a subsequent clarifying statement said “police do not have legislative authority to arrest on this occasion, unfortunately the officers involved and their supervisor were unaware of this.”

A police spokeswoman explained that the type of the warrant which applied to the woman did not support an arrest.

The woman has received a personal apology from Paul Taylor, the Acting Assistant Commissioner for the Northern police region.

She will also be reimbursed a part of her fine, because there was a miscalculation of the outstanding debt.