US security contractor Blackwater, under investigation over incidents in Iraq, has defended its actions in a 16 September shooting in which 11 Iraqis were killed.

Blackwater founder and former Navy SEAL Erik Prince claimed, in testimony prepared for the US House of Representatives committee, that his staff 'acted appropriately' on that day in a very complex war zone.

He said there has been a rush to judgment based on inaccurate information, and many public reports have wrongly pronounced Blackwater's guilt for the deaths of varying numbers of civilians.

Iraq's government has been strongly critical of Blackwater, which provides security for the US State Department in Iraq, and has called the shooting a crime.

A US congressional committee has found that Blackwater has been involved in 195 shootings in Iraq over the past five years.

Last night, the committee published the new details about the activities of Blackwater in Iraq. It said it had uncovered an incident where a drunken Blackwater contractor killed one of the Iraqi Vice-President's guards.

That contractor was transported out of Iraq inside 36 hours with the co-operation of the US State Department. Compensation was offered to the family of the guard.

The committee's report also found the State Department adopted a similar approach when other Blackwater contractors became involved in the killing of innocent Iraqis.

This report is expected to heighten debate over the role of private security contractors in Iraq.