Pierce Brosnan this morning paid tribute to "a beautiful woman" after the tragic loss of his close friend Beau St Clair to ovarian cancer.

Beau, who was Pierce's producing partner for over 20 years, passed away at her home in Malibu over the weekend.

"Farewell my Darling Beau Marie… We made memories in the movies we made, and a deep friendship in the life we shared," the Irish actor wrote on Instagram today.

In a further statement released through his publicist, he mourned the loss of his "dearest friend" who had "fought this insidious disease valiantly for ten long years."

Variety reports that Pierce visited with Beau just a few hours before she passed away.

Pierce and the 69-year-old California native founded their production company Irish DreamTime in 1996, and together worked on films such as Evelyn, The Nephew and a remake of The Thomas Crown Affair.

Beau's death is no doubt made all the more difficult for Pierce by the fact that his daughter and first wife Cassandra both suffered from the same disease.

Charlotte Brosnan died of ovarian cancer in 2013, 22 years after her mother's passing in 1991.

"To watch someone you love have his or her life eaten away bit by bit by this insidious disease, that kind of sorrow becomes an indeliable part of your psyche," the actor revealed at a Stand Up For Cancer event last year.

"I held the generous, strong, beautiful hand of my first wife Cassie as ovarian cancer took her life much too soon.

"And just last year, I held the hand of my funny, wonderful daughter Charlotte before she too died from this wretched, inherited disease."