A passenger ferry leaves a wharf at Watsons Bay as a thick blanket of smoke hangs over parts of Sydney following New South Wales Rural Fire Service (RFS) hazard reduction burns, Sept 14, 2023. (PHOTO / AP)

SYDNEY - Australian police confirmed on Wednesday that a man has been arrested following the discovery of three bodies in Sydney's northwest.

According to the New South Wales (NSW) Police Force, the 49-year-old man was placed under arrest at 11:20 pm local time on Tuesday.

NSW Police Force Detective Superintendent Danny Doherty said at a press conference that the three victims were from one family and they were known to the 49-year-old taekwondo instructor, as the seven-year-old child regularly attended classes at the academy

He currently remains in a hospital to receive treatment for his injuries and he will be charged with murder.

Just before 10:30 am local time on Tuesday, officers were called to Watkins Avenue in Baulkham Hills, where a 39-year-old man was found dead at the scene and appeared to suffer several fatal stab wounds.

READ MORE: Aussie PM backs parliament motion for Assange's release

Two hours later, the bodies of a 41-year-old woman and a seven-year-old boy were located at a martial arts academy on Daking Street in North Parramatta.

READ MORE: Australia Prime Minister Albanese engaged to partner

NSW Police Force Detective Superintendent Danny Doherty said at a press conference that the three victims were from one family and they were known to the 49-year-old taekwondo instructor, as the seven-year-old child regularly attended classes at the academy.

READ MORE: Australia to double naval warships

"What we will allege is that the 49-year-old is the only person responsible and we will allege that he is responsible for the murder of all three victims," Doherty added.