Reports emerged on Saturday afternoon that Griffiths had been arrested following an incident in a supermarket and Hibs later confirmed the 22-year-old had been involved in a police matter.
But the on-loan Wolves striker started Sunday's 0-0 Scottish Premier League draw against Aberdeen and Williams came to his team-mate's defence after the game.
Williams said: "Sparky, in and around the football club, is fantastic.
"He's a hard worker and we don't have any problems with him at all, either in training or the games. His ability is there for all to see.
"There are little controversies that follow him, and whatever reasoning or background is between him and them. We're just happy to have him at the club for the ability he brings."
Williams, who saved Niall McGinn's penalty at Pittodrie, added: "I don't know much about what's gone on. I think he's been a little bit unfortunate and a bit naive at the situations he gets himself in.
"Everyone's spoken to him at length. James McPake speaks to him well, and the manager speaks to him at length.
"He's not a vindictive or nasty person. You see him day to day, and there's not a bad bone in his body, so I'm sure whatever keeps getting him into trouble can be addressed.
"He's got everything you need to be a top, top footballer, and he's showed that this season. We as a group know the talent he brings, and welcome him with open arms every day."
Lothian and Borders Police would not confirm or deny that Griffiths had been involved in the incident in Tesco in Corstorphine, Edinburgh.
A police spokesman said: "A 22-year-old man has been arrested and charged in connection with an alleged shoplifting incident in the Tesco store at Meadow Place, Edinburgh, on Saturday January 26. He will appear in court at a later date."
A Hibernian spokesman said: "The club is aware of an alleged incident which took place on Saturday afternoon involving the player. This is now a police matter."
Earlier this month, Hibs said they would discipline the player following a tweet that was criticised by anti-racism campaigners.