In love letters to Prince Charles (search), Camilla Parker Bowles (search) told how she yearned for him and urged her lover to withstand "the onslaughts of that ridiculous creature," his wife, Diana, a newspaper reported Thursday.

The Daily Mail published details of letters it said had been shown by the princess to her biographer, Andrew Morton (search).

Diana had found them when she searched her husband's briefcase looking for evidence of his affair with Parker Bowles, the newspaper said.

According to the Daily Mail, Parker Bowles urged Charles not to feel guilty about their liaison and promised to be his "forever."

She describes how her "heart and body aches" to be with him. "I yearn to be with you day and night, to hug, comfort and love you," she writes to the man she calls "my most precious darling."

Morton met Diana in 1991 while researching his biography, "Diana: Her True Story," which revealed the princess' bulimia, loneliness and distress at her husband's unfaithfulness.

In a now-famous 1995 TV interview given two years before her death at age 36 in a Paris car crash, Diana said there had always been three people in her marriage — a reference to Parker Bowles. Diana and Charles divorced in 1996 after 15 years of marriage.