Police checking out reports of an overcrowded daycare in Colorado at first found no kids there at all — then made a shocking discovery.

Day care workers had hidden 26 preschoolers in a basement behind a false wall, authorities said.

Cops responded to the Play Mountain Place in Colorado Springs on Wednesday and while they didn’t see any kids at first, they began hearing noises coming from below, officials said.

The sounds were coming from a phony wall which hid a secret staircase to a finished basement where two adults and the 26 kids were, authorities said.

None of the kids — who were all under the age of 3 — appeared to be injured or held against their will, police said.

The day care’s license was suspended, but no one was charged in the incident.

With Post wires