Detective Shaq's David Beckham Wallet Caper

Who woulda thunk it ... Shaquille O'Neal found a lost wallet on the ground that belonged to none other than ... David Beckham!!

Shaq -- a Florida reserve cop -- stumbled onto the case Monday on the grounds of a hotel in Bev Hills. Check out the vid ... Shaq put his detective skills to good use and delivered a clear message for Becks -- holla at your boy!!!

Beckham was staying at the same hotel, and we're told Shaq beelined it to the front desk and left a message for the soccer star in his room. They met up and Becks got his wallet back.