The former EastEnders actor had been cast as dwarf Fili in the Lord of the Rings prequels, but his departure was confirmed by director Peter Jackson on his official Facebook account yesterday.
Writing on Twitter, Kazinsky noted that a health problem is the reason he quit his role in the J.R.R. Tolkien adaptation.
"Thanks for all your support, Peter and team have been the most wonderful and supportive team to work for and it's with a truly sad heart that things have turned out this way," he wrote.
"The Hobbit will go on to be as great as i've seen and I will miss the family and friends that i've here, From every disaster i've tried to make an opportunity. "john d rokerfeller"(sic)"
Martin Freeman will lead the cast of The Hobbit, which sees series stars Sir Ian McKellen, Andy Serkis, Orlando Bloom, Cate Blanchett, Elijah Wood and Ian Holm reprising their roles from the original trilogy.
Watch Peter Jackson's first video blog from the set of The Hobbit below: