Lawyers for Van Morrison are threatening Chicago Review Press that it could be in for legal trouble if it goes ahead with plans to release an unauthorized biography of the rock star next month.

Can You Feel the Silence? by rock biographer Clinton Heylin presents Morrison as a gifted musician and troubled man. It also, according to letters sent to Chicago Review by Morrison's lawyers, libels him with lies about his sex life and violates the copyright on his songs by reprinting excerpts of their lyrics. One letter cautions, "In the event of any acts of copyright infringement by you our clients will not hesitate to enforce their legal rights in this matter."

Other warnings from Morrison's legal team focus on damning claims about the performer's personal life. The book makes "outrageously false allegations that our client has been guilty of inappropriate and improper sexual conduct," according to one letter from the attorneys.

Morrison's lawyers have already initiated legal action in the U.K., where Penguin has temporarily suspending shipping the book after selling 7,000 copies out of a 7,500-copy first printing.

The book's U.S. editor, Yuval Taylor, calls the attorneys' warnings "an annoyance and an amusement" and said they won't affect publication plans. CPR has set a first printing of 6,000 and plans to release the book in September.