BBC News - US web traffic rerouted via China Telecom
The incident, which happened for 18 minutes last April, is published in a report by the US-China Economic and Security review commission.
It found that China Telecom sent incorrect routing information, but it is not clear whether it was intentional.
It comes amid continuing discussions in the US and the UK about cyber-security.
Among traffic rerouted via China was that destined for the websites of the US Senate, the Office of the Secretary of Defence, Nasa and the Commerce Department, the report said.
"Evidence related to this incident does not clearly indicate whether it was perpetrated intentionally and, if so, to what ends," according to the draft report obtained by Reuters.