An investigation into allegations that Iraqi civilians drowned after British soldiers forced them into rivers following the 2003 invasion has been given evidence from a former army officer who says the practice of “wetting” was relatively widespread.

The former captain in the Irish Guards, in a witness statement to the Iraq fatality investigations, has claimed that senior officers had been aware that troops were adopting the practice as they struggled to contain an outbreak of looting.

The allegation has emerged shortly before the Chilcot inquiry publishes its long-awaited report on lessons to be learned from the UK’s involvement in the 2003 invasion.

A number of Iraqis who drowned are said to have been victims of the practice – known as “wetting” to British troops – of forcing suspected looters into rivers and canals.