Aaron Armstrong, 25, was discovered on Tuesday at a property in Northumberland.
The day before, he posted an emotional tribute to his late girlfriend online saying: "Just wish I could cuddle you all day miss you so much."
Gradon, 32, a former Miss Great Britain, was found dead at her family house on 20 June.
A Northumbria Police spokesperson said: "At around 12.20pm today [10 July] police received a report from the ambulance service that a 25-year-old man had been found deceased at a property on Furnace Road in Bebside, Blyth.
"There is not believed to be any third party involvement."
After Gradon's funeral, five days ago, Armstrong posted a picture of the order of service with a caption that read: "I love you with all my heart my beautiful angel I'm absolutely heartbroken I can't stop crying."