Tesla Inc. used humans to remotely control certain capabilities of its Optimus robot prototypes during a recent event designed to drum up investor enthusiasm for upcoming products, according to people familiar with the matter.

Workers stationed elsewhere oversaw many of the interactions between the humanoid machines and visitors to last week’s “We, Robot” showcase near Los Angeles, said the people, who asked not to be identified as they spoke. discussed the company’s activities. The Optimus prototypes could run without external control with the help of artificial intelligence, the people said.