The robot, that was seized by police as evidence, in Cologne, Germany, on Sunday.
Cologne Police/AP

Police in Germany have launched an investigation into possible sexual assault after a robot controlled by two teenage boys allegedly grinded against a 16-year-old girl and touched her buttocks.

The incident occurred in the city of Cologne in the western state of North Rhine-Westphalia late on Sunday night.

The 16-year-old owner of the robot and his 19-year-old companion filmed the alleged attack and live-streamed it on social media, according to police.

The girl was outside a fast-food restaurant between 11.45 p.m. and midnight local time with female friends aged 17 and 18. The robot, which was around 1.20 meters (120 cm) high, approached the girl from behind and carried out the actions, police said.

Emergency services were dispatched to the scene, where they found the alleged assailants and discovered the robot in the trunk of a vehicle, according to police.

Authorities seized the robot and mobile phones belonging to the two suspects.

Video footage circulating online shows a robot dressed in a white vest with a gold chain and sunglasses approaching women on the streets and making sexually-explicit gestures.

Authorities are looking into whether the robot’s movements were pre-programmed or deliberately being controlled at the time of the incident.