Newly released documents show undercover officers mingled with oil and gas protesters during a peaceful demonstration in a Denver suburb last May, providing "critical information" to commanders.
But Lakewood police said Thursday the officers were there only to keep the peace. Spokesman Steve Davis says they weren't gathering information or posing as protesters.
Davis says the critical information referred to in the document was that none of the protesters intended to be violent or get arrested.
The Intercept website obtained the documents through an open records request and published them Tuesday. Police confirmed they were authentic.
The protest was at a hotel where a federal agency was auctioning oil and gas drilling rights on public land. There was no violence and the sale went off as planned.