Two guides on alternative medicine backed by the Prince of Wales should be withdrawn because they contained misleading and inaccurate claims about its benefits, an academic said.
The criticisms came from Edzard Ernst, Professor of Complementary Medicine at Exeter University, who with science writer Simon Singh wrote to the Times on the issue.
But in a statement On Thursday, The Prince's Foundation for Integrated Health (FIH), said: "We are disappointed that Professor Ernst has chosen to promote his new book through yet another attack on The Prince's Foundation for Integrated Health, a charity dedicated to helping people lead healthier lives."
Professor Ernst on Thursday levelled his criticisms at Complementary Health Care: A Guide for Patients, and the Smallwood Report, which tackled the cost effectiveness of complementary therapies.
The guide, and the Smallwood Report - which was commissioned by the Prince and not published by the FIH - came out in 2005.
Professor Ernst said the healthcare guide and the report contained errors and were "equally misleading".
He said if patients used treatments which were "useless and perhaps dangerous" the "danger is obvious".
Professor Ernst said the Smallwood Report was aimed to influence politics and Ministers, which was not his role at all.
"If that influences our health policy in a misguided way we will spend our healthcare funds unwisely," he said.
Professor Ernst and Mr Singh next week publish a new book Trick of Treatment? Alternative Medicine on Trial.