A Republican-controlled congressional committee has blocked a Democratic legislative attempt to obtain more information from the Pentagon concerning its investigation of alleged torture of Iraqi prisoners by U.S. soldiers and civilians.

A "resolution of inquiry" can be used by members of the House of Representatives when they feel a certain part of government is not providing all the information lawmakers want. If they oppose the aim of such a resolution, majority lawmakers can vote it down at the committee level, in that case sending it with an unfavorable recommendation, to the full House for a vote.

The resolution voted on Monday by the House Armed Services Committee asks that Defense Secretary Donald Rumsfeld turn over any photographic, video, or written information produced as part of an investigation into events at Iraq's Abu Ghraib prison.

That investigation was headed by Major General Antonio Taguba, who testified before House and Senate committees in May about his findings. He concluded, among other things, that a failure of leadership led to alleged torture of Iraqi prisoners.

Democrats have pressed for an independent congressional probe of torture allegations, saying the Pentagon has been slow to respond to requests for additional information. Republicans say investigations already underway should be sufficient, saying Democrats are demanding new information without having thoroughly reviewed thousands of documents already provided by the Pentagon.

Congressman Duncan Hunter, chairman of the House Armed Services Committee, said the attempt to request more information under the resolution amounted to "changing the goalposts".

"The idea that we are going to send a message back now, that somehow we have been stonewalled [obstructed] when they sent us 6,000 pages, and only four members of the committee have had the time to read them so far, does not make sense," says Mr. Hunter. "It also sends a false message, it implies that somehow that we're not getting facts, in fact we're getting more facts then we can digest. So I don't think we should start doing business by resolutions of inquiry."

But the top Democrat on the committee, Congressman Ike Skelton, insists information provided so far by the Pentagon did not include documents, five of which have been the subject of recent news media reports, that Congress should see:

"In all respect, this issue is one of credibility of this committee, but it is larger than that. It is the credibility of the United States of America to be able to investigate the problems and do proper oversight under the Constitution," says Mr. Skelton.

Congresswoman Heather Wilson is a Republican on the committee. She joined Democrats in supporting efforts to obtain additional documentation from the Pentagon.

"We have serious and important duties here to discharge, and that requires the tedious review of documents," she says. "We must ask for those documents from the Department of Defense."

In the end, the House committee voted down (28 to 21) the Democratic effort to demand more documents from the Pentagon.

Consideration of the resolution came at the beginning of a week when several hearings dealing with Iraq will be held, including two about Iraqi perceptions of the United States, and the status of U.S. forces in Iraq.