The son of Sunni leader Adnan al-Dulaimi and one of his guards have been linked to explosives found in a house in Baghdad, Iraqi military spokesman Brigadier General Qassim Ata said on Saturday.
"We found explosives stored in a house that was given by Dulaimi's son Mekki to one of their guards to stay in," Ata told reporters. "And Mekki was responsible for all security matters concerning Dulaimi."
Mekki and more than 40 of Dulaimi's guards were arrested on November 30 after Iraqi soldiers found two primed car bombs near the Sunni politician's home in Baghdad's Hail Adel neighbourhood the previous day.
Dulaimi himself was briefly put under virtual house arrest after the discovery.
His detention threatened to derail the country's political process with lawmakers from the National Concord Front the main Sunni political bloc of which Dulaimi is a leader, boycotting parliament.
The Iraqi authorities later said Dulaimi had no connection to the car bombs.
On Saturday, Ata said investigations against Mekki, who is still under arrest, and the guards were continuing.