A prominent far-right activist in Austria says he is being investigated over a possible donation received from the terrorist who opened fire on two mosques in Christchurch.

Martin Sellner, head of the white nationalist group Identitarian Movement Austria, said on social media that police searched his apartment Monday and seized electronic devices.

He said the "disproportionately high donation" came from a person named Tarrant — the same surname as the suspected Christchurch shooter.

Sellner said he's being investigated on suspicion of "forming or being a member of a terrorist organization," which he denied.

Christoph Poelzl, the spokesman for Austria's Interior Ministry, confirmed Tuesday that the country's BVT domestic intelligence agency searched Sellner's home at the request of prosecutors in the city of Graz. He referred further questions to prosecutors, who couldn't immediately be reached for comment.

At least 50 Muslims were killed and as many injured on March 15 when a terrorist -- identified as Australian-born Brenton Tarrant, 28 -- entered the Al Noor and Linwood mosques in Christchurch and shot worshippers in cold blood, including four children younger than 18.

Australian Brenton Tarrant was arrested within an hour of the mosque shootings and has been charged with murder.