On Sunday, the head of parliament's integrity commission, Sabah al- Saadi, told legislators that Mishaan al-Jubouri, who heads a small bloc in the 275-seat parliament, had misused funds earmarked for an oil pipeline protection force in 2005.
The vote in favour of lifting his legal immunity is unprecedented but largely symbolic since Mahmoud al-Mashhadani, parliament speaker, said al-Jubouri was no longer in Iraq. Al-Jubouri has an outstanding year-old arrest warrant against him.
"The accusations are dangerous because they are related to Iraq's economy," al-Saadi told parliament.
"According to investigations by the integrity commission, he used up 110 billion Iraqi dinars every month," he said, citing an amount roughly equivalent to $75 million.
Al-Jubouri could not be reached for comment on Sunday.
Corruption, especially in the oil sector, is thought to be rampant in Iraq. Oil accounts for nearly all of Iraq's revenue and corruption drains away billions of dollars desperately needed to provide Iraqis with basic services.
A spokesman for Iraq's Independent Integrity Commission could not confirm al-Saadi's figures but said Iraq's defence ministry had evidence and witnesses against al-Jubouri.
"The case involves Mishaan and his son, Yezin. It dates back to the time when he was directly and indirectly responsible for protecting oil pipelines from sabotage," spokesman Ali al-Shabout said.
"He's accused of several things, including registering fake names to overcharge for things such as meal allowances."
Oil pipelines in the area north of Baghdad have been under frequent attack by anti-US fighters in the past three years, leaving Iraq increasingly dependent on southern oil fields for exports.
Al-Jubouri was close to the former government of Saddam Hussein. He fell out with the Iraqi authorities in mid-1990s and became a fierce Saddam opponent, and worked with many of yesterday's opposition parties.
He is well known for declaring himself the governor of Nineveh (Mosul) after the US-invasion in March 2003. He is also known for declaring himself the sole connection between Iraqi fighters and US forces in Iraq. Anti-US fighters' factions announced they had nothing to do with al-Jubouri.