Undercover police launched an investigation into the inspector from the capital's public transport company ATAC, local media writes, after two tourists reported him for soliciting bribes.
The inspector reportedly asked for €50 in cash from each of the two women instead of issuing them with standard €104 fines when he caught them travelling on a city bus without tickets.
He then told them that if they paid him cash on the spot they would save money and avoid having their names added to a non-existent "register of offenders."
The tourists paid up and boarded another bus with the inspector at his request, before asking him for a receipt.
They said the ticket controller printed off a receipt for one €104 fine and reassured them they wouldn’t have to pay it, before making a hasty exit.
Suspicious, the women immediately went to the police, who said undercover officers soon caught the inspector in the act of extorting cash from another pair of passengers.
Atac said in a statement: “The facts described are absolutely intolerable and, if the accusations are confirmed, the company will adopt an exemplary sanction commensurate to the seriousness of the behaviour, which does not do justice to the great daily work of our inspectors.”