The former actor, who played Augustus Gloop in the beloved 1971 film, admits he missed his old pal on the big screen during the last years of his life.

Bollner, who is now a tax lawyer in Munich, Germany, says, "I was very sad, of course. We knew he was quite ill and had not been out in public for some time. It was disappointing not to see him on screen these last few years.

"He never made it to any shows (fan conventions) with the Wonka kids. We do a lot of shows in the U.S. signing autographs and talking to people. The last one was in Los Angeles.

"He was a great guy. We had a lot fun making the movie. He was very funny and he made a lot of jokes. I didn't have a huge amount of contact with him as my English was very poor at that time and his German wasn't so good... I regret not speaking to him again in the years after the film when my English had improved."

Bollner joins Wonka kids Denise Nickerson and Julie Dawn Cole among those who have paid tribute to Wilder.

Rocker Alice Cooper has also offered up his thoughts about the actor's passing, revealing he truly enjoyed working with Gene on the set of his short-lived sitcom, Something Wilder.

"I count working with Gene Wilder on his TV sitcom Something Wilder to be one of the most precious memories of my entire career," the rock icon writes in a statement posted to his Facebook page. "Doing 'one-on-one' comedy with Gene was like jamming with THE BEATLES. It doesn't get any better. Gene Wilder is IRREPLACEABLE and will always be an American treasure."

Meanwhile, rockers Coldplay also paid tribute to Wilder at a gig in Denver, Colorado on Monday night, dedicating their rendition of Pure Imagination, the song he sang in Willy Wonka & the Chocolate Factory, to the late actor.