Missing schoolgirl Bung Siriboon. Photo: Supplied
It's six years to the day since Bung Siriboon left for school but never made it, and authorities will be stepping up their efforts to find her.
Photos of the missing Boronia school girl will be up on billboards around Wantirna South for the whole month, in the hope of sparking someone's memory.
Police have confirmed the space have been donated by Civic Guides Media.
Bung left her home in Elsie Street, Boronia around 8.30am on Thursday 2 June, 2011, but never made it to school.
Detective have previously said they were looking for a car similar to a white 1971-1973 Holden HQ Kingswood station:
Officers believe a car similar to this may have been involved. Photo: Vic Police
There were reports a girl similar to her description was seen in a white station wagon on the day of her disappearance, but police wouldn't confirm that.
There is a $1 million reward for information about her disappearance.
Boon's family still believe she will be found, her step dad Fred Pattison, saying they haven't given up hope.
“We have to believe she is still coming home,” Mr Pattison told News Corp.
“It doesn’t get any easier (as time passes), it gets worse.
“We miss her; it’s been hard and it continues to be hard.”
Anyone with new information about the disappearance of Bung Siriboon is urged to contact Crime Stoppers on 1800 333 000 or visit www.crimestoppers.com.au.