The former Argonaut player and current vice-chair of the team reportedly threw one of his four championship rings into the crowd for fans to look at during the game when a woman walked away with it.
Constable Gary O'Brien said in a release Saturday night that the 30-year-old Nanaimo woman later returned the ring to RCMP officials, who are making arrangements to return it to Clemons.
"She feels absolutely terrible about the situation and told the officer she wants Mr. Clemons to know she had no intention of keeping it and just wanted to do the right thing by turning it in," O'Brien said.
The woman told police she was sitting in the front row when Clemons threw the ring into the crowd. She also said she waited for security to retrieve the ring but left after no one approached her.
The Argos reached out to fans via Twitter on Saturday morning, asking them to be "on the lookout" for the ring and to contact police with any information.
Clemons began his CFL career in 1989, signing with Toronto as a free agent after a brief stint with the NFL's Kansas City Chiefs, and played until 2000.
The Florida native recorded 3,840 all-purpose yards in 1997, surpassing the single-season record he set himself years earlier. The record held until 2012 when Argos receiver Chad Owens broke it.
Clemons was named the CFL's Most Outstanding Player in 1990, and won four Grey Cups — three as a player and one as a head coach — all for Toronto.