An Interior Ministry official said unidentified armed men entered the businessman's office in the al-Mansur district in western Baghdad at 11am (0700 GMT) on Saturday and took him along with $150,000, the official said.
No further details are available.
Also on Saturday, three Falluja police officers were found fatally shot in the nearby town of Karma, 10km east of Falluja, said police 1st Lieutenant Muhammad Ibrahim from Falluja.
The victims - identified as 1st Lieutenant Mahir al Dulaimi, Lieutenant Ali Abd Allah and Sergeant Aziz Jihanhad - had travelled to Karma three days ago and their families lost contact with them, he said.
In Baghdad, unknown gunmen travelling in two cars opened fire and killed a Ministry of Interior police employee on Friday night, police Captain Muhammad al-Ubaidi said on Saturday.
Lieutenant Colonel Abd al-Qadir Wahab was killed in his car on his way home, he said.
In separate attacks, armed attackers ambushed several Iraqi police patrols throughout Baghdad on Saturday, injuring three officers, police said.
The morning attacks occurred in the eastern neighbourhood of New Baghdad, southern Dora and western Saidiya, police said.
A blindfolded, bullet-riddled corpse of a man in his 50s was found just outside Baghdad, said police Lieutenant-Colonel Sabah Hamid. The man had died some time ago, he said.
On Friday night, police discovered the body of the third of three brothers abducted in northern Baghdad earlier this week.
Two corpses had already been found on Thursday, according to 1st Lieutenant Thair Mahmud on Saturday.
Two of the brothers were police officers while the third was an imam.
Meanwhile, loyalists of al-Qaida's Iraq frontman, Abu Musab al-Zarqawi, said they captured Algerian charge d'affaires Ali Belaroussi in Baghdad on Thursday in a statement posted on the internet on Saturday.
"The head of the Algerian delegation was taken from the most secure region under the protection of the Crusader (US)" and Iraqi forces, said the Al-Qaida Organisation in the Land of Two Rivers.
Al-Qaida has confirmed the capture
of Algeria's envoy Ali Belaroussi
The statement, the authenticity of which could not be verified, did not mention Belaroussi's colleague, Ezzedin Ben Kadi, who was kidnapped along with him.
Also on Saturday, the 15 Sunni Arab members of the committee charged with drafting a new Iraqi constitution boycotted a fresh meeting, jeopardising the panel's chances of completing its work by a 15 August deadline.
"None of the Sunni members of the committee attended the meeting," Ayad Al-Samarrai, spokesman for the Islamic Party, a leading Sunni faction, said.
Ayad al-Samarrai (R) : No Sunni
members were at the meeting
The 15, who were co-opted on to the parliamentary committee after a widespread boycott of Janaury elections by the disgruntled former elite left it largely unrepresented in the legislature, had announced on Thursday they were suspending their participation in its meetings.
The move followed Tuesday's murder of two Sunni members of the committee who were shot and killed in broad daylight in the capital.
The 15 are demanding an international investigation into the killings.
Their withdrawal from the drafting committee risks undermining the legitimacy of the final document.
It could also result in the new constitution being turned down in a referendum scheduled for mid-October, as the rules stipulate that the charter fails if it is rejected by two-thirds of the voters in any three provinces.
Sunni Arabs form a majority in al-Anbar, Salah al-Din and Nineveh provinces.