The decision followed a request by anti-corruption NGO Transparency International that had said public statements made by government officials and politicians gave merit to the polygraph test and claimed the tests would improve the quality of governance and the effectiveness of Congress.

"By obliging these politicians to undergo certified polygraph tests they will be discouraged to commit crimes or tell lies about their behavior inside and outside the Congressional chambers," Transparency International claimed.

According to the Inspector General Alejandro Ordoñez, who in his ruling excluded himself from the obligatory tests, "the undergoing of lie detector tests can help congress regain the confidence of the Colombian people."

Dozens of lawmakers told press they applauded the measure and vowed to comply to the tests. However, in a leaked letter to the Inspector General, the newly elected Secretary General of Congress requested the results of the tests to remain confidential, which was granted by Ordoñez.

"What we must avoid is that lawmakers acting in good faith are subjected to political persecution. To guarantee this, the results of the tests will not be made public and used only for internal evaluation," the Inspector General explained.

"Understand that lying, unless under oath, is neither a criminal offense nor against the congressional codes of conduct," Ordoñez added.