The suspected gunman who tried to shoot-up a mosque in Norway in an attempted terrorist attack has been accused of killing his teenage stepsister because of her Chinese heritage, possibly on the same day of the foiled attack.

Olso police said Tuesday that 17-year-old Johanne Ihle-Hansen was shot four times — three in the head and once in the chest — by a .22-caliber rifle that was later found in the car of her 22-year-old stepbrother Philip Manshaus.

Manshaus was arrested after opening fire Aug. 10 at the Al-Noor Islamic Center in Baerum, an Oslo suburb. The attack was ultimately thwarted by a 65-year-old who overtook Manshaus.

The body of Ihle-Hansen was later found dead inside Manshaus’ home.

An autopsy report could not determine when exactly Ihle-Hansen was killed other than it was on the same day that Manshaus stormed the mosque, police said.

Police official Pal-Fredrik Hjort Kraby told TV2 that evidence, including Manshaus’ explanation and lack of struggle “support[s] the version that [Ihle-Hansen] was killed because of what the attacker considers as race, because she was of Asian origin.”

Authorities had been mulling possible motives for her murder, including that it was a racist crime and that she may have learned of Manshaus’ plan to shoot up and mosque and tried to stop him.

Manshaus, who has confessed to the mosque attack, was reportedly inspired by the shooting at two mosques in New Zealand that left 51 dead and the Aug. 3 massacre in El Paso, Texas, where 22 were slain.

With Post wires