GATINEAU, Que. - A search warrant filed in court says an ongoing argument over aboriginal issues at the home of Sen. Patrick Brazeau escalated into a physical and sexual confrontation and back-to-back 911 calls to local police.

Court documents say Brazeau, 38, has formally pleaded not guilty to charges of assault and sexual assault.

His arrest on Feb. 7 came a day after a Senate committee announced it had hired independent auditors to examine Brazeau's housing expense claims and those of two other senators.

Now, the police warrant details allegations by a woman in Brazeau's home who says he punched her, choked her, tore her pants off and pushed her down a flight of stairs, breaking the railing.

The complainant also alleges Brazeau aggressively grabbed her breast and another area of her body, called her vulgar names in French and English, spit in her face, and tore up a bra and blouse she was trying to pack in a suitcase.

The warrant seeks to find the bra, blouse and a button that was torn from her pants as her zipper broke.

None of the allegations have been proven in court.

Brazeau could not be reached Tuesday for comment.

The former national chief of the Congress of Aboriginal Peoples — which represents off-reserve natives — has been an outspoken critic of some factions of the aboriginal movement, including the Idle No More protests. He has also publicly criticized Chief Theresa Spence of Attawapiskat, whose liquid-only protest diet this winter became a lightning rod for aboriginal dissent.

The search warrant says the complainant and Brazeau were having an ongoing disagreement over the native file that had begun the night before.

According to the search warrant, a crying woman initially called police in Gatineau, Que., across the Ottawa River from the national capital, just after 9 a.m., on Feb. 7 but hung up. It said she called back two minutes later to say she was being beaten.

The warrant said when police arrived at the home, Brazeau had locked himself in a room upstairs.

Brazeau was immediately kicked out of the Conservative caucus by Prime Minister Stephen Harper, who had made him the third youngest appointee ever to the upper chamber in December 2008.

Brazeau was forced by his Senate colleagues to take a leave of absence from his duties following the charges, but continues to collect his $132,000-a-year salary.

He is currently out on $1,000 bail under orders not to possess firearms and to stay 150 metres away from the complainant. His next court appearance is set for March 22.

A brash, outspoken figure on Parliament Hill, Brazeau was a former Canadian Forces member and holds a black belt in karate. The heavily-tattooed Algonquin wore his hair in a long pony tail until he cut it off following his loss to Liberal MP Justin Trudeau in a charity boxing event last year that raised $230,000 for the Ottawa Regional Cancer Foundation.

Note to readers: This is a corrected story. An earlier version wrongly said Brazeau was the youngest appointee to the Senate.

© Copyright 2013