She died on Sunday, August 2, reported Female First. She was also Fox's manager for the last 16 years.
Her demise was announced on Fox's Twitter page. The 49-year-old singer has appealed for privacy while she grieves.
"It is with great sadness we announce the passing of Myra Stratton. She was Samantha Fox's partner and manager for the last 16 years. She bravely fought cancer for the last two years but lost her battle on Sunday. Samantha asks for privacy as she grieves," a statement read.
"Sam is absolutely devastated. She adored and loved Myra and her loss has created a huge hole in her life. Myra was Sam's manager but also her best friend and lover. It's a huge loss for her," a source said.
Fox first met Myra in 2003 and at the time she said she is the only person she has ever been in love with.