Jack Black has been sunbathing in a wet suit on holiday in Hawaii.

The 'Kung Fu Panda 2' actor has been baffling other guests at the upmarket Four Seasons resort in Kona by donning a huge rubber suit, but never taking out a surfboard or even hitting the beach.

An onlooker told the New York Post newspaper: ''Jack was poolside in a surf suit down to his ankles, long-sleeved. Not surfing, just lounging with his wife and kids. He looked pretty funny. If that's not a Christmas present, then I don't know what is.''

Jack, 43, is known to be a little conscious of exposing his flesh. Although he seemingly spontaneously rips off his shirt in the video to his band, Tenacious D's track 'Tribute', he insists it was all meticulously planned.

He said: ''It was in the script. I would never expose my nips just for fun. That's serious business.''

Jack - who has sons Samuel, six and Thomas, four, with wife Tanya Haden - has also previously said he'd like to lose weight so he can appear in more nude scenes.

He said: ''When I saw my rear end in my nude scene in 'Margot at the Wedding', it actually had a double chin. I've joined a gym because the next time you see me naked I'll be trim.''