Greens senator Sarah Hanson-Young has lashed out at a fake social media post under her name purportedly painting the Sydney siege gunman as a victim.

Senator Hanson-Young has referred the fabricated post circulating on Facebook to Australian Federal Police.

• Sydney siege not a ‘story’ – it’s a sad reality of life

The fake post has been copied off Senator Hanson-Young’s December 16 statement on the social media site expressing sympathy for siege victims Tori Johnson and Katrina Dawson.

In the original post, the senator calls on the nation to unite following the tragedy and commends police and emergency services for their work on the 16-hour siege.

But the photoshopped version veers away sharply, blaming the government and racism for the outcome.

“The ultimate victim here was Man Haron Monis,” the fake post reads.

Senator Hanson-Young said on Monday it was disappointing her statement was altered in “such a sinister way” to politicise the tragic event.

“My thoughts remain with the victims and their families,” she said.