Baltimore's Harbor Tunnel was temporarily shut down when cash spilled out of an armored truck and onto the roadway inside.

The Maryland Transportation Authority Police say in a news release the tunnel was closed in both directions for about seven hours Wednesday night after money began falling out of the rear door of a Brinks armored truck about 8 p.m. The tunnel reopened about 3:40 a.m. Thursday.

Officers say a preliminary investigation shows the truck's door security malfunctioned.

Police refused to say Thursday how much money was recovered, but said not all of it has been returned.

Authorities say anyone who took some of the cash that spilled in the tunnel can return it to Maryland Transportation Authority Police before 5 p.m. Saturday without being prosecuted for theft.