Bung's stepdad hopes she is still alive five years after disappearance

The stepfather of a Melbourne schoolgirl who vanished five years ago said he hopes she is still alive.

Fred Pattinson's 13-year-old stepdaughter Bung Siriboon went missing while walking the short distance from her Boronia home to Boronia Heights College on June 2, 2011.

Mr Pattinson told A Current Affair he hopes Bung, who would now be 18, is "with someone who has taken her to raise her".

"I hope she's still alive. She was such a lovable kid."

Police are now offering a $1 million reward for information that may help solve the case.

"Nobody just vanishes. Someone somewhere knows something," Mr Pattinson said.

Police have followed up numerous leads and checked the alibis and movements of 250 sex offenders but failed to discover what happened to Bung.

Two years after the teen went missing a man told police that he ran her over with his car and dumped her body in a reserve near the schoolgirl's home.

But no body was found and the man was not charged.

A teenage girl from Bung's area once told police that a man had tried to abduct her but later admitted that she had made the story up.