Alan Hallman, a longtime Progressive Conservative operative who was expelled from the party in January, was arrested Friday night near the PC leadership convention in downtown Calgary.

According to Calgary police, officers were called to the Telus Convention Centre just after 11 p.m.

Hallman was detained by security prior to police arriving at the scene. He was arrested and charged with "common assault," police said. Hallman was released from custody with a promise to appear.

Duncan Kinney, the executive director of Progress Alberta, said he didn't see the altercation himself but was at the convention centre at the time. He filmed a conversation between a security guard and police after the incident, which he later uploaded to Twitter.

"Based on conversations that I had overheard between the security guard, who was allegedly assaulted, and police, Mr. Hallman was in the process of being removed from the Telus Convention Centre," Kinney said. "He was given a 48-hour trespass ban and at that point, according to the security guard, Mr. Hallman took a swing at him."

"After that altercation, he was put in handcuffs and police arrived."

RAW VIDEO: Aftermath of Alan Hallman altercation. Security guard describes incident to police <a href="https://t.co/y2W9mNI5jy">https://t.co/y2W9mNI5jy</a> <a href="https://twitter.com/hashtag/ableg?src=hash">#ableg</a> <a href="https://twitter.com/hashtag/pcldr?src=hash">#pcldr</a> —@ProgressAlberta

In a statement, a spokesperson for Hallman acknowledged the former PC organizer was involved in an altercation "at or near the PC leadership convention."

"Hallman regrets any inconvenience or upset that may have resulted from this incident. However, he commits to full cooperation with all involved to ensure speedy and appropriate resolution to this matter," the statement said.

Worked for Kenney campaign before suspension

Before he was suspended from the party on Jan. 15, Hallman worked as a "field organizer" for Jason Kenney's leadership campaign.

Hallman was informed of his suspension in an email from Katherine O'Neill, the president of PC Alberta, who said the decision stemmed from comments he made on social media directed towards two Progressive Conservative Association of Alberta members.

Along with a year-long suspension, Hallman was also barred from attending all PCAA events and was forbidden from using any PCAA data, including membership lists and leadership data.