BAGHDAD - A probe into whether US Marines covered up the circumstances in which up to 24 Iraqis were killed in the city of Haditha last year is complete and a top commander is reviewing it, the US military said today.

Lieutenant General Peter Chiarelli, head of US ground forces in Iraq, received the findings of the investigation and would either approve them, add his own conclusions or request more information from the investigating officer.

A separate Naval Criminal Investigative Service probe could lead to charges including murder.

Major General Eldon Bargewell led the fact-finding team looking at not only whether Marines involved in the Nov. 19 incident lied about what happened, but whether senior Marine Corps officers sufficiently examined the veracity of the troops' account.

"While the Naval Criminal Investigative Service was requested to and is examining potential criminal offences arising from the incident, Major General Bargewell was tasked to examine official reporting and communication flow surrounding the operations, type of training the forces received prior to and after their arrival in theatre, and command climate within the unit," said the US military statement.

Defence officials previously have said a preliminary military probe conducted in February and March found evidence that the Marines involved in the incident gave a false account of what happened.

The Haditha case, which has drawn comparisons with the 1968 My Lai massacre in Vietnam, has eroded popular support for the Iraq war in the United States.

Iraqi Prime Minister Nuri al-Maliki, who has come under mounting pressure to deliver on promises of delivering justice to Iraqis resentful of the American presence, has said he would ask Washington for a copy of the Haditha investigation.

Chiarelli has no time limit for deciding what action to take.