Royal Couple Prince Charles And Princess Diana/ file photo/REUTERS/Handout/Files
Former press officer of the couple will be revealing all in his upcoming book of memoirs. REUTERS/Handout/Files

Princess Diana and Prince Charles' marriage has been embroiled in another controversy. A new book published by journalist Heribert Schwan reportedly has some explosive interviews with former German chancellor Helmut Kohl where some deeply unflattering comments about royals have been revealed.

According to the reports by Daily Mail, Mr Kohl told Mr Schwan that he was not fascinated with Prince Charles marriage with Princess Diana. "Her marriage was an absolutely ******* affair," he told Mr Schwan, according to the further reports by Express.

The book by Schwan is titled as "Legacy: The Kohl Transcripts" and it is based on the 600 hours interviews with Kohl. It has also been revealed by Guardian that the book has been published against the wishes of the chancellor.

The excerpts from the book have been published in a magazine Der Spiegel and now the full book is available in the bookstores. The book has also suggested that if Princess Diana had become the Queen, directly things would have been different, according to reports by Daily Mail.

"But like this she had to travel around, talk to mayors and so on and then she withered away," the excerpt from the book further read. The lawyers of Kohl are reportedly demanding deletion of 115 quotations from the book, as per Gaurdian. It has also been reported that journalist Schwan was previously asked by court to return the tapes, however, the process was delayed and the book was apparently published without Mr Kohl's permission, according to the website.

The book also has insipid revelations about world leaders such as Bill Clinton and Margaret Thatcher. In the last few months this is the second book which has revealed alleged inner secrets of Princess Diana and Prince Charles' life. Dickie Arbiter, a former royal spokesperson revealed the inside affairs Princess Diana's life and her purported marriage troubles with Prince Charles. The book was titled "On Duty with the Queen."