Ottawa police say they hope a pedestrian struck downtown can help them track down the vehicle that left the crash scene.

Police say a man in his 50s was struck in front of the Library and Archives Canada building on Wellington Street just east of Bay Street.

The crash happened at about 10:50 p.m. Sunday when the man was struck by an unknown vehicle. The driver then left the scene, police said.

A taxi driver then found the man lying injured on the road and called 911.

The man was conscious when paramedics arrived and they said he is in hospital in serious condition.

Police are also looking for witnesses to the crash and they want anyone who has more information to call 613-236-1222, ext. 2481.