Martine McCutcheon's brother has died at the age of 31, just days before his wedding.
The former Eastenders actor, 46, said on the social media platform that John suddenly died two weeks ago, just one month before he was set to tie the knot with his fiancée.
She wrote in the sad post: "My heart is forever broken… My baby brother, my gentle giant, sadly passed away, suddenly, 2 weeks ago. He was 31 years old."
She continued, explaining they are still at a loss regarding the cause of Laurence's death: "There is no medical explanation as to why we lost him so soon and whilst we investigate further, we are having to accept that nothing will bring our boy back to us.
"L.J (Laurence John) was born when I was 15 years old and from the moment I first held him in my arms, I felt so proud and fiercely protective of him. He was such a character!
"He made us all laugh and loved nothing more than making a plan, having a great playlist, bringing people together and generally having a giggle. He hated the thought of a party ending and so was always on to the next thing!"
She went on to explain how her brother had 'mild' special educational needs, but thanks to "unwavering love, support and a commitment to himself, he took hold of life with both hands and smashed through any expectation we had of him."
"He would genuinely blow us all away at times!"
Detailing his upcoming wedding, Martine wrote: "LJ fell in love and was due to get married next month… I was asked to be bridesmaid and the last time I saw him, was a few days before he passed.
"He, Jack and his future stepson had been to try on their wedding suits and then they came back to have dinner with his fiancée and the family to see our new home."
"He looked so tanned, tall and handsome. The best I've ever seen him.
"My heart aches for all who have lost him. But my heart breaks for our mum, his dad John & his step parents. You should never outlive your children."
She concluded in the sad post: "I'm scared to live without you LJ but I know you will want us to truly live, laugh and love in your memory. I will try I promise."
If you have experienced a bereavement and would like to speak with someone in confidence, contact Cruse Bereavement Care via their national helpline on 0808 808 1677.
Featured Image Credit: @martinemccutcheon/Instagram