Officers have pulled a body from the River Aire near the Cardigan Fields retail park in Leeds.
The search for the body, in the river close to Kirkstall Road, was launched last night (Tuesday), after a 17-year-old man was seen entering the water at about 6.45pm.
A police helicopter, officers, paramedics and firefighters were all called to the scene.
The body was recovered from the water in the River Aire at about 1.30am today (Wednesday), according to a West Yorkshire Police spokeswoman.
"Enquiries are ongoing," she added.
At about 8.20pm last night, a tweet from the official Twitter account for NPAS, the force helicopter based at Carr Gate in Wakefield, confirmed it was assisting in the search after a man was seen entering the water.
The busy retail park is home to Vue cinema, Hollywood Bowl and a string of popular restaurants.
It is also close to Leeds Industrial Museum.