A Wisconsin school district is investigating a photograph of a group of high school boys giving what appears to be a Nazi salute.

Baraboo Superintendent Lori Mueller said she became aware of the photo on Monday after it was posted on social media.

Ms Mueller says the photo appears to have been taken last spring and was not on school grounds.

Ms Mueller says the photo does not reflect the district’s values and that administrators will pursue appropriate action.

Baraboo police are also investigating.

The photo of more than 60 male students dressed in suits shows many with their right arm extended upward.

The Auschwitz Memorial tweeted that the photo is why it works hard “to explain what is the danger of hateful ideology rising”.

Baraboo is a town of about 12,000 about 115 miles north-west of Milwaukee.