The Iraqi Interior Ministry on Monday arrested a businessman accused of embezzling $2.5 billion, in the latest major corruption scandal to rock the war-torn country since 2003.
The embezzlement was disclosed earlier this month, with 3.7 trillion Iraqi dinars fraudulently paid to five companies by the General Commission of Taxes.
The investigation is under way but no findings yet have been released.
The Interior Ministry identified the businessman as Nour Jassim, 42, the chief executive of Al Mubdioon Oil Services company.
Mr Jassim was arrested late on Monday at Baghdad International Airport as he was trying to flee the country, the ministry said.
Legislator Mustafa Sanad, who has been following the case, described him as "the main accused" in the case, saying he hired a private jet and planned to head to Istanbul Ataturk Airport.
The businessman is one of four who are sought by the authorities over the case. The whereabouts of the others is unknown.
Trading companies and people who have dealings with the government are required to deposit a specific amount of money, from which taxes will later be deducted.
Afterwards, the companies and people can apply to withdraw what is left from their deposits.
According to the findings of internal investigation conducted by the Finance Ministry, the companies, at least three of them established last year, submitted fake documents for their claims.
The money was paid through 247 cheques between September 9, 2021, and August 11, 2022, from the commission's account at the state-run Rafidain Bank.
The Supreme Judicial Council said a Baghdad court had been investigating the case since August and described those behind it as an “organised network linked to influential figures”.
Arrest warrants have been issued and the court has heard evidence from some Finance Ministry and General Commission of Taxes employees, the council said.
Iraqi caretaker prime minister Mustafa Al Kadhimi hailed "the heroes" of the security forces and judiciary authorities.
Mr Al Kadhimi defended his government, which faces accusations of corruption and mismanagement mainly from Iran-backed political parties.
"From the outset until the last days of this government, we continue fighting corruption, exposing those responsible and arresting criminals," he said.
"Pursuing theft of public money and bringing perpetrators to justice is our priority."
Corruption has been rife in Iraq since the 2003 US-led invasion that toppled Saddam Hussein. Many politicians have been arrested or removed from office for the practice.
Iraq is considered one of the most corrupt countries in the world. It ranked 157th out of 180 nations on Transparency International’s 2021 corruption index.