Pamela Tascas has a recurring nightmare where her son Trevor calls out to her, but as she responds, he gets further away.
"I wonder now, on the last day of his life, did he think of me before he closed his eyes?" she said.
"Did he think, 'Mum, I need you now'?"
Trevor Tascas disappeared 16 years ago and police firmly believe he was killed.
On Tuesday, they put up a $1 million reward for information leading to those responsible.
Mr Tascas' Geelong roommate Lawrence Butler was charged with his murder and in 2009 was sentenced to 23 years in prison.
However, his conviction was quashed on appeal two years later and, in 2013, he was retried for manslaughter and found not guilty.
Mr Butler's girlfriend Jodi Harris was sentenced to three years' jail after pleading guilty in 2009 to being an accessory to manslaughter and obtaining property by deception.
Police say their investigation is open to different lines of inquiry and they require new information to take the case forward.
"In 16 years, friendships change, allegiances change, new friends come on the scene (and) people learn things," Detective Acting Inspector Tony Combridge said.
No one had been ruled out of the investigation, including the two people originally charged, he said.
Through tears on Tuesday, Ms Tascas begged for someone to come forward. She had been stuck in a time warp since 2005, she said.
"It breaks my heart to think someone's out there living a lie," she said.
Mr Tascas went missing between October 7 and 10, 2005. He was 27 and living on Thatcher Court at Whittington in Geelong.
He had sporadic contact with his family at the time, but his mother became increasingly concerned when she did not hear from him for weeks, reporting him missing on April 1, 2006.
Investigators believe Mr Tascas had a dispute with his roommate before he disappeared and, afterwards, a number of his possessions were sold and his dog was given away.
His bank account showed a number of withdrawals in July and August 2006, but they weren't made by Mr Tascas. His phone was last used on October 7, 2005.
Ms Tascas described her son as a cheeky boy who loved his younger sisters Kirsty and Leanne, but was often in trouble at school and with the police.
He was the joy of her life, who ended up on the wrong side of the tracks.
On Tuesday, she pulled out a small, red cardboard box containing photos of Trevor.
She has a dollar note he kept as a souvenir as well as a lock of hair from when he was a baby.
"This is all I have of Trevor," Ms Tascas said. "His whole life's in this box."
