Police have searched a Victorian river close to where missing mum Karen Ristevski went missing a month ago.  Water police circled a section of the Maribyrnong River about 4.30pm on Friday after receiving a tip-off from a member of the public.  They called off the effort as the sun set.  A police spokesperson would not confirm if any clues had been discovered or whether or not the search would continue on Saturday.  "Police won't be providing running commentary on this matter," Victoria Police spokeswoman Belinda Batty told AAP.  Mrs Ristevski, 47, disappeared from her Avondale Heights home on June 29 when she went out for some fresh air after a heated discussion with her husband.  She has not used her bank accounts or phone since she went missing.  The Herald Sun reports police were searching near the Maribyrnong Rd bridge, with people at the nearby Anglers Tavern watching on as the water police boat moved up and down the river.  SES crews, water police and motorbikes searched the Maribyrnong River and surrounding areas around a fortnight ago.  Police set up an information caravan this week in the hope it will generate some fresh leads with a mannequin dressed in Mrs Ristevski's likeness.  Detectives also doorknocked the area and handed out flyers on Wednesday.  "We are treating it as a missing persons case, but the longer she remains missing the more difficult it becomes," Det Insp Dennis told reporters on Wednesday.  Police confirmed they were speaking with a number of people in relation to the case.  Mrs Ristevski's husband Borce was previously questioned by police and released pending further inquires.  Anthony Rickard - Mr Ristevski's son from a previous relationship - also says he was questioned.
A public tip off has led police to search the Maribyrnong River in the hunt for Victorian mum Karen Ristevski who went missing last month.