Former Interior Minister Mariusz Kaminski and his deputy Maciej Wasik were released after 9pm (local time).

They were jailed this month after being convicted of abuse of power in previous roles. Both men went on hunger strike, declaring themselves “political prisoners”, and their imprisonment sparked massive protests by tens of thousands of PiS supporters.

President Duda pardoned both politicians after their initial convictions in 2015 but Poland's Supreme Court deemed his move invalid, saying presidential pardons cannot be applied before a final verdict in the case is issued.

They were sentenced to two years in prison in December, when a new centrist coalition took power in Poland. Within days of their imprisonment, Duda announced that he had begun the process of pardoning them for a second time.

"I call on the Minister of Justice to immediately release both of them," Mr Duda said in a statement.

New Prime Minister Donald Tusk has vowed to repeal some PiS policies and punish officials accused of wrongdoing during their time in power. Tusk says he wants to bring Poland back in line with European Union democratic standards.

Mai Van (according to Reuters)