November 17, 2006 11:45 AM ET

THE HAGUE, Netherlands - Dutch military interrogators abused dozens of Iraqi prisoners in 2003, dousing them with water to keep them awake and exposing them to high-pitched noises and strong lights, a Dutch newspaper reported Friday.

Prime Minister Jan Peter Balkenende told the national broadcaster NOS that "if this is true, it is shocking" and said the allegations must be investigated.

The report by the left-leaning national daily De Volkskrant was published five days before national elections, which Balkenende's center-right Christian Democratic Appeal is favored to win.

Responding to the allegations in the report, which cited no sources, Defense Ministry spokesman Joop Veen was quoted as telling the newspaper that "things happened that did not go according to instructions."

Veen was in a meeting with Dutch Defense Minister Henk Kamp early Friday and did not immediately return phone calls seeking comment.

The alleged prisoner abuse happened when Dutch troops were stationed in Iraq's southern Muthana province. The Netherlands had about 1,400 troops stationed there until their withdrawal last year. There are now 15 Dutch soldiers still serving in Baghdad training Iraqi forces.

According to De Volkskrant, the interrogations were carried out by members of the Dutch Military Intelligence and Security Service in November 2003 in buildings of the Coalition Provisional Authority in Samawah, 230 miles southeast of Baghdad.

Prisoners were forced to wear darkened goggles, which were at times removed as bright lights were shone in their eyes, De Volkskrant reported. They also were kept awake for extended periods by being soaked with water and exposed to high-pitched sounds.

Femke Halsema, leader of the minority Green Left opposition party, said the allegations appeared to have been covered up by officials in the military and demanded parliament be recalled so lawmakers can question the defense minister.

Balkenende originally sent troops to Iraq in August 2003 but would not extend their deployment despite pressure from Washington and London, due to widespread opposition from the Dutch public.

The commander of Dutch troops in the province reported the incidents to Dutch military police, according to the report, and there was an internal investigation, but there were apparently no prosecutions linked to the abuse and the matter was never made public.

In Britain, an ongoing court-martial of seven soldiers is the nation's most significant military trial since World War II. The soldiers are accused of mistreating detainees in Iraq in September 2003.

Last month there was an outcry after a newspaper published photos of German troops posing with a skull in Afghanistan. The photos, published in the daily newspaper Bild, provoked widespread expressions of disgust and triggered a review of training for foreign deployments.