Queensland police have charged a senior One Nation adviser with multiple counts of assault.
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Raw Vision: One Nation adviser arrested
One Nation adviser Sean Black is arrested in Brisbane on assault charges.
Sean Black, a media and policy adviser to outspoken senator Malcolm Roberts, was taken into custody in Brisbane on Wednesday.
He was later charged with three counts of common assault and three counts of assault occasioning bodily harm. Details of the allegations against him cannot be reported for legal reasons.
He later appeared in Brisbane Magistrates Court and was granted bail.
Mr Black has been under investigation since a complaint was lodged last August, as revealed by Fairfax Media. It is understood police arrested him after he failed to appear for a scheduled interview on Wednesday morning.
In February, Senator Roberts defended Mr Black over media reports about him, branding them "fake news".
"While it's terrible that Pauline and I are subjected to lies and smears to try and discredit us politically, it's totally unacceptable that when they can't find dirt on us the media go after our staff," Senator Roberts said in a Facebook post.
"I have been working closely with Sean for the past five months and he is a great asset to our team and to Pauline's team, both as a hard working aide and as a personal friend. I have seen no evidence of the caricature he is painted to be, he loves his family, has a great sense of humour and is extremely well liked by all those who associate with him.
"Sean has my full support and will continue to have my full support in this office for as long as I am an elected official."
Mr Black declined to comment on the allegations at the time.
A spokesman for party leader Pauline Hanson said the allegations against Mr Black had been "noted".
"Mr Black is entitled to the presumption of innocence," he said.
"Many people have been charged and have been found innocent. The allegations against Mr Black do not relate to any parliamentary duties. They are private matters and should not deflect from the serious issues Australia is facing and which the Australian Parliament needs to focus on."
Mr Black has been a controversial figure in Queensland politics, starting out in the 1990s as a Labor operative tasked with destroying Pauline Hanson's party when she first burst onto the scene.
He left the ALP after being caught up in a vote-rigging scandal detailed in the Shepherdson corruption inquiry. He was never charged with any crimes but subsequently gravitated towards conservative politics.
In 2008, he was elected to the Logan City Council, where he was accused of bullying and flying into fits of uncontrollable rage.
At one stage, he was banned from entering council chambers or dealing with staff after a string of complaints of intimidation.
The mayor at the time said he had a "sad history of unacceptable behaviour" and ordered special security arrangements for any meetings he attended. Colleagues said he was disruptive and chaotic.
At the time Mr Black admitted to raising his voice and swearing but said the ban was a result of his political enemies trying to silence him.
With One Nation on track to make big gains at the next Queensland election, sources have named Mr Black as a potential future state leader.
One Nation has been contacted for comment.