Jessie J has been left devastated following the sudden death of her longtime security guard Dave.

The British singer took to her Instagram page on Sunday (30Dec18) to share a series of pictures of herself with her colleague and close friend, as she remembered some of their best times together in a heartfelt tribute.

"The love you had for your children. Was everything. We would laugh till we cried nearly everyday," she wrote. "We talked about our dreams. We talked about what our biggest fears were. You weren’t just my security, we ARE family. 4 years. Me and you."

Recalling how Dave used to constantly make her laugh, Jessie also wrote that he was by her side during the difficult times as well.

"When you came to see me when I was in hospital to cheer me up and I was out of it on anaesthetic and we again just laughed," she wrote. "When I was terrified on that flight from Dubai to London because of the turbulence and you held my hand for 8 hours. I will never forget that."

Paying tribute to Dave and the way he looked after Jessie and her fans, the singer called him a "gentle giant" as she praised him for being her "rock" while she was in Australia for her judging role on The Voice.

Concluding her post, Jessie wrote: "I wrote this because I want everyone to remember the man you were. You were a gentle giant with a heart so big everyone felt it.

"I love you so much. We were supposed to meet for hot chocolate next week. I miss you. I will see you on the other side one day. Rest easy Dave / give your Dad a hug from me."

It's unknown how Dave died.