Luke Gosling - the member for the Darwin-based seat of Solomon - was in custody after being arrested on Thursday over allegations he assaulted NT Administrator David Connolly earlier in July.
Mr Gosling, 54, was later bailed after being charged with two counts of assault and was set to appear in Darwin Local Court on September 1.
The federal MP was arrested after investigations began last week, police said on Thursday.
The NT administrator is a position similar to a state governor, who represents the nation's head of state King Charles, with Mr Connolly sworn into the role in February.
The alleged incident reportedly occurred at the NT Thailand Grand Festival in Darwin on July 18, with Mr Gosling posting photos from the event on social media that day.
Mr Gosling, a retired army officer who has represented Solomon since 2016, released a statement after his arrest.
"The Northern Territory Police have released a statement on this matter," he said.
"I am co-operating fully with their inquiries."
He had denied the allegations when they were first reported last week.
''These are ridiculous allegations that I categorically deny," he said in a statement.
"I've had no dealings with the administrator since congratulating him following the announcement of his appointment late last year."
Mr Connolly was a controversial appointment after coming under fire over his previous "offensive" social media posts.
They appeared to denigrate women and Indigenous people, share transphobic claims and make jokes about domestic violence.
He apologised over the posts but about 100 protesters vented their anger outside NT parliament and clashed with police when he was sworn in, resulting in an Aboriginal elder's arrest.
Prime Minister Anthony Albanese would not be drawn on Mr Gosling's arrest.
"There is a legal process underway. It would be inappropriate to comment further," a spokesperson said on Thursday.
5°C