A substance believed to be potentially toxic brought into Health Sciences Centre Saturday by an unknown man has proved to be benign.

A healthcare worker approached an individual near the William Avenue entrance at about 8 a.m. and experienced strange fumes. Two hospital workers and the individual who brought the substance into the hospital in a bag were decontaminated.

Almost a dozen police and emergency vehicles blocked off William at the HSC all morning and until about 1 p.m. However, the hospital's emergency services were able to continue on as normal.

Officials did not release what the substance turned out to be.

William Ave., which was closed to all traffic between Sherbrook Street and Tecumseh Street by the Winnipeg police earlier this morning, has been reopened.