That the two most famous auction houses in the world, Sotheby's and Christie's, conspired to fix commissions is agreed by all. That the conspiracy cost clients up to $400 million in extra commission fees from 1993 to 1999 is alleged.
But just how far up the companies the conspiracy went will be determined by a trial that is fascinating New York.
Sotheby's company chairman and primary shareholder, Mr Alfred Taubman (77), a shopping complex multimillionaire from Michigan who bought the auction house in 1983, is facing charges that he colluded with Christie's to fix commissions and divide up business between them.
He faces up to three years in prison and enormous fines if convicted in the anti-trust prosecution.
The prosecutor said on Friday at the opening of the trial that he was relying on the jury to conclude that Mr Taubman and his Christie's counterpart, Mr Anthony Tennant, met secretly to do the deal in 1993.
Not so, says Mr Taubman, who blames the then company CEO, Ms Diana "Dede" Brooks, now the principal witness against her former boss.
"Whatever Ms Brooks chose to do, she did completely on her own, without my knowledge or approval," Mr Taubman said in the only public statement he has given on the topic.
"If the need arises, I will vigorously defend myself against any charges."
Ms Brooks, in court last October for her guilty plea, insisted she had only acted "at the direction of a superior at Sotheby's". As CEO, she had only one boss: Mr Taubman.
Competition was cut-throat in the early 1990s, with agents from the two auction houses scrambling for business and offering commissions on sales as low as 0 per cent. The stakes were huge. Sotheby's auctioned van Gogh's Irises for $53.9 million and a Renoir for $78.1 million. Christie's handled the entire art collection of multimillionaire Victor Ganz and turned it into $206.5 million, a record for a single estate.
Then, suddenly in 1995, the competition faded. Christie's announced a new sliding scale for commissions and a few weeks later, Sotheby's matched its rival's policy.
Anti-trust investigators have made their cases against the two companies from documents handed over by the Christie's CEO, Mr Christopher Davidge, which implicated Ms Brooks and himself.
The documents showed that the two houses, in clear breach of competition laws, were not only setting commissions together, but trading lists of clients, and comparing salaries to avoid losing staff.
A series of civil suits from sellers were quickly filed against both houses. And federal prosecutors handed down indictments against Sotheby's, Mr Tennant, Mr Taubman, and Ms Brooks.
In late September, each company agreed to pay $256 million in damages, for which the government agreed to drop charges against the houses, but not against the principals involved.
