Dikembe Mutombo's fancy Rolls Royce Phantom was smashed up while he was having a Father's Day dinner with his family ... and now cops are on the hunt for the culprit.
The 52-year-old NBA legend was dining at the Landmark Diner in the Atlanta area late Sunday evening -- when someone ran into the restaurant and yelled out that multiple cars had been vandalized in the parking lot.
When Dikembe checked out his 2009 Rolls, he noticed both front windows and the rear passenger windows were busted, according to the police report obtained by TMZ Sports.