A scream in the night, glass smashing, and dogs barking - these were the first signs that something terrible had happened in a suburban Sydney street.

Since then, police have revealed this was a highly unusual case of mistaken identity that resulted in the kidnapping of an innocent 85-year-old grandfather.

And on Tuesday morning, the worst fears of his Sydney family were realised: police announced they believed they had found the body of the widower, almost two weeks after he was taken.

Today, crime reporter Riley Walter on a case that has gripped Sydney.