A bad-tempered row erupted in the world of classical music after experts clashed over the authenticity of a Beethoven manuscript that is up for auction.
The handwritten score is going under the hammer Sotheby's on Tuesday, where it is expected to fetch up to £200,000.
But a Manchester university academic has insisted there is "no doubt" that the document was not penned by the composer and clashed with the auction house's expert.
Professor Barry Cooper told the BBC Radio 4 Today programme: "There are several aspects which prove absolutely that it couldn't possibly be Beethoven's hand. For example, the natural signs are completely different from any natural signs in any genuine Beethoven script."
The manuscript is described as Allegretto In B Minor For String Quartet composed and written by Beethoven on November 29 1817 in Vienna.
Simon Maguire, director of books and manuscripts at Sotheby's, said two world-class specialists had examined the document to assess and verify it.
He claimed Beethoven experts "think it is more a matter of Prof Cooper misreading the manuscript than anybody else, let alone Beethoven".
"I don't agree with his analysis of what the manuscript says," he said.
In the increasingly fractious exchange, Mr Maguire said the professor had "resolutely refused" to visit the auction house to look at the manuscript.
As the pair raised their voices and talked over each other, Prof Cooper said there was no need to make the journey to London because he was able to see "perfectly clearly" that it was not penned by the composer, and branded the situation "absurd".
The two men continued to clash until Today presenter Justin Webb brought the interview to an end, telling the pair: "It's a tough world, the world of Beethoven."