UPDATE: A MAN has been arrested in connection with the murder of Victorian woman Sarah Cafferkey.
Special Operations Group officers arrested the 47-year-old man in Hawthorn about 12.30pm.
A police spokeswoman said he's currently in custody and assisting police with their enquires.
Ms Cafferkey, 22, was last seen by her family on November 9.
Her body was found in a Point Cook house on Saturday and was formally identified yesterday.
Police say the arrested man is also from Bacchus Marsh.
The arrest prompted police to warn the public about posting prejudicial material online, which has been a concern in other high-profile cases.
"The community is reminded that comments on social media sites may potentially affect the outcome of court matters relating to this investigation," a police statement said.
"We request people refrain from posting hateful or inciteful comments on these sites."
Police have not revealed how they linked the woman's disappearance to finding her body in the Point Cook home.
Most neighbours in the new outer suburb couldn't recall seeing anything suspicious, but one resident remembered hearing power tools being used late at night.
"They were doing some mechanical work in their garage, using power tools and things like that," the man told the Nine Network.
Ms Cafferkey's car had been found abandoned elsewhere in Melbourne.
Police discovered a yellow Ford sedan on the Western Highway near Bacchus Marsh on Friday and were investigating if it had any links with the case.
Ms Cafferkey's ex-boyfriend had been ruled out as a suspect.