HOBART, AUSTRALIA - JULY 29: Michael Hibberd of the Demons reacts after missing a shot on goal during the round 19 AFL match between the North Melbourne Kangaroos and the Melbourne Demons at Blundstone Arena on July 29, 2017 in Hobart, Australia. (Photo by Quinn Rooney/Getty Images)

Authorities fear for the brother of Melbourne defender Michael Hibberd, who has now been missing for over a day, according to SEN's Sam Edmind.

Hibberd's brother and another man left the Flinders boat ramp before 6am on Sunday for a fishing trip in Westernport Bay, and haven't been seen since.

The Mornington Peninsula was thrashed by extreme winds and rain on Sunday, with a max gust of 63km per hour being recorded.

The search began last night when a concerned friend contacted authorities just after 9pm when the pair still could not be reached.

The search operation is headed by the Water Police, Coast Guard, Victoria Police Airwing and Volunteer Marine Rescue agencies.

The duo's fishing vessel was described as a three-metre aluminium "tinny" with an outboard motor.

Victoria has banned recreational fishing as part of its social isolation orders.