Sen. Patrick Brazeau has formally entered a not guilty plea to charges of assault and sexual assault.

Brazeau, 38, was charged earlier this month after a 911 call brought police to his home in Gatineau, Que., just across the Ottawa river from the national capital.

His arrest 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.

Brazeau was immediately kicked out of the Conservative caucus by Prime Minister Stephen Harper, who had appointed the former national chief of the Congress of Aboriginal Peoples to the Senate in 2008.

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