Fredericton blogger Charles LeBlanc was arrested Wednesday at the legislature for trespassing.
LeBlanc has been banned from the legislature grounds for six years.
He was reportedly trying to get an interview with Energy Minister Margaret-Ann Blaney, who had announced earlier in the day that she is resigning from politics to become the chief executive officer of Efficiency New Brunswick.
Fredericton police responded to a call from the legislature's sergeant-at-arms Daniel Bussières.
The Fredericton Police declined to comment, or even confirm that it was LeBlanc who was arrested.
In a written statement, Cpl. Rick Mooney said police responded to the legislature "regarding a complaint of assault.
"Officers arrested a 52-year-old male at that location for assault and subsequently transported the man to the Fredericton Police station," Mooney said.
The man was released from police custody about 4 p.m., he said.
"The matter is still under investigation and police expect to have more to say on the matter on Thursday morning."
The arrest comes just days after LeBlanc and his lawyer called for a public inquiry into the Fredericton Police Force's handling of a raid at LeBlanc's home in January.
LeBlanc, who writes a controversial blog that is often critical of politicians and police officers, had his computer seized and was informed he would be facing charges of criminal libel.
He was accused of damaging the reputation of a city police officer in blog posts last summer.
But on May 4, the provincial government announced it would not be proceeding with criminal libel charges against LeBlanc.
The attorney general said in a statement that section of the Criminal Code of Canada has been deemed unconstitutional in other jurisdictions and it was unlikely a New Brunswick court would come to a contrary decision.
Last week, Attorney General Marie-Claude Blais told CBC News she's not ruling out a provincial inquiry into the case.
Meanwhile, the city has launched a review of whether police acted properly.
Fredericton Police Chief Barry MacKnight has stepped back from the third-party investigation. He said the process must be viewed as "credible and beyond reproach."
MacKnight had previously said he would pick who would conduct the review and establish the terms of reference.
LeBlanc could be facing an assault charge.
The banning notice he received in 2006 stated he would be charged with assault under the Criminal Code of Canada if he refused to stay away.
LeBlanc has often been spotted around the legislature since the ban was implemented, but he's only been arrested once before, in April 2009.
LeBlanc, who had been attending a protest on the legislature's front lawn, was facing charges of mischief and assault.
But the charges were never formally filed with the courts.
LeBlanc was permanently barred from entering any buildings or stepping on any property within the provincial legislature district in June 2006.
The barring notice, posted on his blog, accused him of demonstrating "unacceptable behaviour within the legislative precincts, which has included harassment and disrespectful behaviour toward legislative staff, members of the Security Detail and members of the public."
At the time, legislature officials said the ban was to ensure employees could work in a secure environment free of harassment.