Elton John's father-in-law has died aged 90.

The Rocket Man star's husband David Furnish announced the passing of his father Jack in an emotional post on Instagram on Sunday, alongside two old black and white pictures of his dad when he was younger, and two of Jack holding his grandchildren - Elton and David's sons Zachary, nine, and Elijah, seven - when they were newborn babies.

"My father passed away peacefully last night at the age of 90. Dad overcame the traumas of his own family being torn apart by both World Wars," David wrote in the accompanying caption. "He sought solace and comfort in the loving arms of my mother, and built a platform of solid and loving familial stability in which we could all flourish.

"Dad was an old-fashioned conservative, who viewed life through the limited lens he was given from a heavily disrupted upbringing. Like most conservatives, Dad feared what he didn’t know. But he never ceased to amaze me with his capacity to learn and grow, as his sons expanded his horizons through our own life experiences. He was present at the birth of both of my sons and full of joy for Elton and me."

He concluded his post by writing: "Dad is with Mum now. The place he always wanted to be most. Thank you for all that did for me Dad. You encouraged me to be independent and strong. To believe that I could achieve my goals in life through hard work and kindness. Lessons that I pass on to my own sons every day."