Only days after a British court rejected a lawsuit by two writers who claimed that author Dan Brown had plagiarized their writings in The Da Vinci Code, a Russian art historian is also threatening to take Brown to court. Mikhail Anikin, a Leonardo da Vinci expert in the Hermitage museum's Western European art department, told the London Times that in 1998 he had shared his controversial ideas about Da Vinci's Mona Lisa painting with visitors from Texas, one of whom asked if he could pass them on to his friend, Brown. Anikin told the Times that he agreed, even giving his theory about the painting a name -- The Da Vinci Code. "When I read the book, I was shocked at its poor quality and because it used my ideas," Anakin told the newspaper. He is demanding an apology from Brown and half the revenue from the book. A film version of the book is due to premiere at the Cannes Film Festival next month.