Jawad Louay al-Yasseri, whose father was then governor of the central province of Najaf, was arrested in 2018 and sentenced to life in prison, which amounts to a 20-year term in Iraq.

On January 10, he and two fellow convicts in the same case were quietly granted a presidential pardon and released.

But the decision caused a stir among lawmakers and journalists who criticised an alleged backroom deal involving the governor, who resigned a day before the pardon was requested.

The president on Monday "ordered the immediate withdrawal" of the pardon and the "arrest of the convicted persons", according to a presidency statement.

The statement said the presidential pardon "formally conformed with the legal and constitutional procedures" but "was not carefully examined" and "did not comply with the strict controls approved by the presidency".

The president ordered a commission of inquiry to complete its work to identify those responsible for the oversight and hold them accountable, according to the statement.

Saleh had ordered on Saturday an "urgent investigation" over the pardon, which was granted upon recommendation from the cabinet.

The ex-Najaf governor, who stepped down in the face of corruption accusations against him, has insisted on his son's innocence and said he was targeted to damage his father's reputation.

In 2019, Iraq was rocked by massive protests fuelled by charges of widespread official corruption, incompetence and withering economic hardships.