Luke Gosling - the member for the Darwin-based seat of Solomon - has been released on bail after being arrested on Thursday over allegations he assaulted NT Administrator David Connolly earlier in July.
Gosling, 54, did not comment as he left Palmerston Police Station after being charged with two counts of assault.
Gosling's lawyer criticised police for placing the MP in custody.
"NT Police released a statement this morning saying that Mr Gosling was arrested. Unfortunately, that happened at his home," Marty Aust SC told reporters on Thursday.
"It's particularly concerning that the police resorted to the power of arrest when they could have dealt with this matter by way of summons or notice to appear."
Mr Aust said his client "utterly denied" the charges and questioned the motivation behind the conduct of the territory's investigators.
"There's a real concern that there's a degree of politicisation in relation to how this matter is being handled," he said.
In a statement posted to Instagram, Gosling said he couldn't say much with his case now before the courts, but described the experience as "strange".
"A big thank you to everyone who's reached out to me and my office with messages of support for me and my family," he wrote.
"It really means a lot. Anyway, we're all cracking on with it.
"I'll stay focused on doing my job and building a stronger Territory and better nation for all of us."
Gosling's arrest came after investigations began last week, police said.
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 Gosling posting photos from the event on social media that day.
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 Gosling's arrest.
"There is a legal process under way. It would be inappropriate to comment further," a spokesperson said on Thursday.
Section 44 of the Australian Constitution disqualifies anyone convicted of a crime punishable by imprisonment for one year or longer from remaining in parliament.
Gosling is set to appear in Darwin Local Court on September 1.