A toddler who was found dead in a creek in Melbourne's north-east was snatched from a pram while walking with her mother in a park on Saturday, homicide detectives say.

Key points: Toddler abducted from pram at Heidelberg West park

Toddler abducted from pram at Heidelberg West park Girl's body found hours later by locals in nearby creek

Girl's body found hours later by locals in nearby creek Police search for man wearing dark clothing

Police search for man wearing dark clothing Attack believed to be random

West Heidelberg residents Michelle and Faye leave a floral tribute for toddler Sanaya Sahib. ( ABC News: James Hancock )

Police said 15-month-old girl Sanaya Sahib, who had been missing since Saturday morning, was found in Darebin Creek in Heidelberg West by four people searching together just before 3:00am.

Detective Senior Sergeant Stuart Bailey said the toddler was with her 22-year-old mother, Sofina Nikat from Mitcham, at Olympic Park about 10:00am, when the little girl was grabbed and taken.

"[Ms Nikat] noticed a male walking towards her, that male has folded in behind her and has then pushed her to the ground, has taken the child from the pram and run in a south-westerly direction on the eastern side of Darebin Creek," he said.

"He crossed over a footbridge that then takes you into the Northland Shopping Centre area and perhaps towards Woods Street.

"This is obviously extremely concerning for Victoria Police if this is a random abduction."

Detective Senior Sergeant Bailey said police believed it was a random attack.

Emergency services conducted a line search of the area on Sunday afternoon to look for clues.

The area where the toddler's body was found at Darebin Creek. ( ABC News: James Hancock )

The man has been described as between 20 and 30 years of age, about six feet tall with short dark hair and not wearing shoes.

Police said he was wearing black pants and a black zipper top.

They said he had dark skin and smelt heavily of alcohol.

Detective Senior Sergeant Bailey said Ms Nikat had tried to chase the man, but was unable to and returned to her friend's home and contacted police.

People have left tributes, flowers and teddy bears at the scene. ( ABC News: Patrick Rocca )

He said authorities had worked hard to find the girl when she was reported missing, but she was found in the early hours by a local family who had once lost a child and wanted to assist.

Police said clothing on the body found in the creek matched that reported on the missing toddler.

Heidelberg West residents Michelle and Faye left a floral tribute near the scene and said they knew of the family.

"I just wanted to put flowers for the baby," Michelle said.

"I couldn't sleep knowing she was out here somewhere.

"I was hoping she was alive."

Anyone who saw the incident has been urged to contact Crime Stoppers.