The arrest of Iraqi electoral commission officials has inflamed political tensions here, drawing accusations on Friday that Prime Minister Nuri al-Maliki aims to destroy the democratic process.

Faraj al-Haidari, the head of the Independent High Electoral Commission (IHEC), was detained on Thursday along with another of the body's members, Karim al-Tamimi.

The Higher Judicial Council said on Friday that "the decision to detain Faraj al-Haidari and Karim al-Tamimi was based on (them paying) real estate registration employees to register pieces of land for them, from the budget of the electoral commission."

The presidency of the autonomous Kurdistan region in northern Iraq said the arrests were an attempt by "those controlling the government in Baghdad" to centralise power and destroy the democratic process.

The arrests are "targeting the independence of the electoral commission, and the goal behind them is to kill the democratic process by enhancing control over an independent institution that is working to make the electoral process work in the country," a statement said.

"It seems that some of those controlling the government in Baghdad are working on proceeding with what they already started a long time ago, to force centralisation and return the political process to the first phase," it said.

Haidar al-Mullah, a leading MP in the Sunni-backed Iraqiya bloc, also strongly condemned the arrests, accusing Maliki of dictatorship.

"When the head of the independent electoral commission is being targeted, it means it is a message from the one who is targeting him that he is above the law and above the political process," Mullah told AFP.

"The one who is standing behind this is the head of the State of Law coalition (Maliki), because he wants to send a message that either the elections should be fraudulent, or he will use the authorities to get revenge on the commission."

"This arrest is an indication that the judiciary has become an obedient tool in the hands of Mr Nuri al-Maliki," he said.

"Today, we skipped the phase when dictatorship is born, and now we moved to the phase when dictatorship is growing in the hands of the prime minister," Mullah said.

The arrests have built on already-existing tension from several Iraqi political crises.

Kurdistan has stopped oil exports, saying Baghdad withheld $1.5 billion (1.2 billion euros) owed to foreign companies in the region. The two sides are also at odds over disputed territory in northern Iraq and dozens of energy contracts awarded by Kurdistan.

And the region gave refuge to fugitive Vice President Tareq al-Hashemi, a Sunni from Iraqiya who is wanted on charges of running a death squad, who has since departed the country.

The Iraqiya bloc has also been at odds with Maliki, accusing him of centralising power. It boycotted parliament and the cabinet from December into late January and early February, respectively.

Haidari, a 64-year-old Shiite Kurd, told AFP by telephone from a police station in central Baghdad where he and Tamimi are being held that his arrest is a move by the State of Law coalition against IHEC.

"I think this is not direct against me ... this is against IHEC, against all the democratic process in Iraq," Haidari said.

He described the issue as being over "three or four" people working for IHEC who were paid 100,000 dinars ($83) for working overtime.

"This situation is very, very normal," Haidari said.

"This case, it's one of the cases which Hanan al-Fatlawi used in the questioning with parliament," Haidari said, referring to an MP from State of Law.

State of Law sought a no-confidence vote on Haidari for alleged corruption in July 2011, but failed because other parties opposed the move.

Haidari said a judge had earlier dismissed the case, but that "Hanan al-Fatlawi took it again to the court, and this time, the judge changed his mind."

He said he believes the case is related to the potential extension by two to three months of the terms for the current IHEC members, which are to expire on April 28.

"This is one of the reasons which pushed Hanan al-Fatlawi and the State of Law to open this case again to prevent us to continue our job," Haidari said.

A parliamentary source said State of Law opposes an extension for Haidari as the head of IHEC.

The United Nations Assistance Mission for Iraq, which has worked closely with IHEC, said it is following the case and that "due process must apply in accordance with the principles enshrined in the Iraqi constitution."