THE US Justice Department was scrambling today to find out who was responsible for the leak of Pentagon documents which appear to detail US and Nato aid to Ukraine.

The documents, which were posted on sites such as Twitter, are labelled secret and resemble routine updates that the US military’s joint chiefs of staff would produce daily but not distribute publicly. 

They are dated from February 23 to March 1, and provide what appear to be details on the progress of weapons and equipment going into Ukraine.

The documents do not detail war plans but they do contradict information that the US has provided. This includes an estimate of between 16-17,500 Russian troop deaths which is significantly lower than the “well over” 100,000 stated by US officials.

The leaked data says the Ukrainians have suffered up to 71,000 casualties.

One US official said the initial documents resemble data produced daily by the joint chiefs, although some numbers are wrong. 

Even if they were legitimate, the official said, the US said they believed there was little real intelligence value to the documents.