Kelly Preston was "very proud" of her last film

He wrote on Instagram: "Off the Rails starring Kelly Preston ... Off the Rails is Kelly's last film - she was very proud of it and of all of the wonderful talent that she got to work with in it. It is available in UK and Ireland theatres starting Friday July 23rd! @offtherailsfilm @bklproductions (sic)"

John previously remembered Kelly on the first Mother's Day since her death.

The 'Grease' star wrote in a poignant and sweet message: "Dearest Kelly, you brought into my life three of the most wonderful children I have ever known. Thank you. We love and miss you. (sic)"

Kelly had been secretly battling breast cancer for two years prior to her death.

At the time of her passing, a spokesperson for the family said: "On the morning of July 12, 2020, Kelly Preston, adored wife and mother, passed away following a two-year battle with breast cancer.

"Choosing to keep her fight private, she had been undergoing medical treatment for some time, supported by her closest family and friends.

She was a bright, beautiful and loving soul who cared deeply about others and who brought life to everything she touched.

"Her family asks for your understanding of their need for privacy at this time."

Kelly and John shared Ella, 21, and Benjamin, 10, as well as Jett, who tragically died in 2009 aged 16.