The homicide squad was called in after Dean McGrath's lifeless body was found at the property on Governor Road at Braeside just before 10am on Friday.

The 41-year-old former senior constable left the force in 2010 with post traumatic stress disorder.

On Thursday, relatives found Mr McGrath's truck parked behind the factory with the keys in the ignition and his belongings inside.

Police said a 45-year-old man went to Mordialloc Police Station early Friday morning and police subsequently checked the factory and made the grim discovery.

Police also arrested another 47-year-old Rosebud man.

Both have been charged with one count of murder.

The men are set to appear at an out of sessions court hearing at the Melbourne Magistrates Court early Saturday morning and were both remanded in custody.

One of Mr McGrath's former colleagues said he was a talented boxer and excellent athlete.

"He was softly spoken, modest, and a really, really good athlete. I just remember him as a good kid," he said.

Tributes have flowed on social media for the married father of two boys.

Roy Corteste, paid tribute to his childhood friend on Facebook.

"RIP Deano watched you grow up in to [a] fine young man," he posted.

"Cherish the memories countless sparring sessions ... condolences to the McGrath family."

Another friend, Scott Bindloss, remembered Mr McGrath as a talented boxer.

"Condolences to the McGrath family on their loss," he posted on Facebook.

"Dean was a much loved boxer from the old Chelsea days. RIP."

Emergency services charity Sirens of Silence also remembered the former police in an online Facebook tribute.

"Another sad loss for our emergency services," it read. "In our Hearts' RIP SC Dean McGrath. Our thoughts are with your family, friends and colleagues."