An MP opposes selective education, then sends his children to private school. A vicar asks his flock to pay for the new church roof, then asks the parish to pay him for painting the vestry. A trader acquires stock he knows is about to rise, then counts the profits. Such cases are, respectively, hypocritical, unethical and illegal. The conflicts of interest are obvious. They would leave most people aghast. Hence the natural concern about the Tate’s purchase of a work by one of its own trustees, Chris Ofili.

Consider the roles of the principal players. The Tate’s policy is to avoid buying work from its own trustees. Yet that is precisely what it did in the case of Mr Ofili’s The Upper Room, a 13-piece work using the artist’s signature elephant dung. Sir Nicholas Serota, the godfather of British modern art and the Tate director, appeared to have doubts about the purchase. Nonetheless, it proceeded.

Secondly, Sir Nicholas and Mr Ofili have both been conspicuously and naturally appealing for funds on the Tate’s behalf. Sir Nicholas asked artistic giants, the likes of Hirst and Hockney, to donate their own works because the Tate could no longer afford to buy those by artists it had made famous. Mr Ofili, who probably falls into that category, issued a similar plea — while selling his own work to the Tate. The work may be a piece of genius, but was justice seen to be done?

Thirdly, many questions need to be answered about the machinations of the deal. Victoria Miro, Mr Ofili’s dealer, appears to have driven a hard bargain with the Tate, which is the job of a clever dealer. But who were the five benefactors who helped with the Tate’s purchase? Did they hold privileged information? And what, if anything, did they stand to gain? Mr Ofili’s works may be wildly original, but there is a danger that this elephant dung will leave a nasty smell.