Michael Mann has been accused of “slicing and dicing” the work of a composer who wrote music for his new film, Blackhat.

Harry Gregson-Williams was one of a group of composers who wrote music for Mann’s hacking thriller, which stars Chris Hemsworth as a rogue computer programmer recruited by the government to catch a cybercrook. In a post on Facebook (since deleted), Gregson-Williams wrote that he was “shocked and surprised” at the music that appeared in the final film.

“I would like it to be known for what it’s worth that the ‘score’ for Blackhat may be credited to me, but contains almost none of my compositions,” he said.

Gregson-Williams went on to describe the “quasi emotional (synth) string pieces” that had replaced his work.

“I was not the author of most of what is now in the movie,” he said. “I therefore reluctantly join the long list of composers who have had their scores either sliced and diced mercilessly or ignored completely by Michael Mann.”

Among the other composers employed by Mann were Atticus Ross, who won an Oscar for his sparse electronic score for David Fincher’s The Social Network. He worked alongside his brother, Leo. Björk producer Haxan Cloak has also said he worked on parts of the score.

Mann has said that Gregson-Williams’s music was edited to fit the tone of his film. “Harry’s a talented composer whose music needed editing and remixing to fit the very contemporary subject and ambitions of my picture,” he told Variety. “It would have been preferable to me, too, if the delivered music could have been used as it was.”

Blackhat, which is released in the US today and in the UK on 20 February, was described as “unsavoury” and “stupid” in a review by the Guardian’s Jordan Hoffman. “Blackhat can’t decide if it is a grim, realistic story from the trenches or cyberwarfare or a giddy, ‘who cares if that makes sense?’ Bond film,” he wrote.