Vancouver police are investigating after a World War II-era mortar shell was discovered in Stanley Park.

The shell, which was found near the HMCS Discovery, has been X-rayed by an explosives disposal unit but the team couldn’t determine whether it’s live or not.

It has since been removed for transport to Chilliwack.

Authorities aren’t sure how the shell ended up in the park, but said it’s likely been there for decades.

Stanley Park has a long history as a strategic military site, and was fortified against potential attacks during both World War I and II.

According to the City of Vancouver, the military took control of Ferguson Point from the park board and constructed an artillery battery and garrison there in the 1930s.

The military also commandeered Third Beach from 1940 to the end of World War II.