Pro-Palestinian supporters damaged Deputy Prime Minister Richard Marles' office.
Protesters doused the MP's Geelong office with red paint, used to symbolize the “blood of children”, on Wednesday evening.
'Stop arming Israel' and 'river of blood on your hands Marles' were written on the outside walls of the Corio members' office in Yarra St.
Red paint was also splashed across the front and side of the building.
Deputy Prime Minister Richard Marles' Yarra Street office was vandalized by pro-Palestinian protesters on Wednesday evening
A police spokeswoman said Ny Breaking Australia officers became aware of the graffiti at around 7am on Thursday and the incident was being investigated.
The building was cordoned off with police tape at 8 a.m. and two officers monitored the area.
Mr Marles said he had been informed of the protester's actions.
“My first concern is always the safety and well-being of my staff,” he said.
The nearby office of Corangamite MP Libby Coker in Armstrong Creek was vandalized by pro-Palestinian supporters last week.
“Many people in our community are grieving and have strong feelings about what is happening in the Middle East,” Ms. Coker said.
“I appreciate and support the right to protest peacefully, but the destruction of property and intimidation of my staff is not the solution to the ongoing conflict.”
Mr Marles (pictured) has been informed of the vandalism and said his 'first concern is always the safety and well-being of my staff'
Mr Marles' office on Brougham Street was the subject of another pro-Palestinian protest last month when demonstrators stormed the building
Last month, pro-Palestinian protesters refused to leave Mr Marles' office on Brougham Street in Geelong after storming in and demanding an end to the war.
Some chained themselves to a ladder, while others held banners reading “ALP SUPPORTS ETHNIC CLEANSING” and “STOP ARMED ISRAEL.”
Victorian Police met the protesters at the scene and arrested five people for trespassing
Anyone with information about the graffiti at Mr Marles' Yarra Street office is urged to contact Crime Stoppers.