On Sunday, actor Emile Hirsch allegedly assaulted Paramount Digital Entertainment vice president Dani Bernfeld at a Sundance party.

At the party, which was held at Tao nightclub, Hirsch was allegedly drunk and began verbally attacking Bernfeld, says Page Six  Hirsch's verbal attack later became physical when the "Into the Wild" actor allegedly pinned Bernfeld against a table and put her in a headlock.

"Emile was aggressively picking on Dani," said a source.

The source claimed added Hirsch suddenly "snapped" and "got even more aggressive."

"He pushed Dani up against a table, and then he put her in a headlock," the source explained.  "He attacked her from behind -- he completely blindsided her after he'd been s--t-talking and was already led away from her once."

According to Page Six, police were called over to TAO nightclub to investigate the incident. Hirsch was not arrested and allegedly cooperated with police officials.

"He calmly waited for the police to arrive and spoke with them until around 5 a.m," the source said. "I can't imagine he'd be involved in anything like this."

Although no arrests were made at TAO, police officials later told Variety that they have continued to investigate the incident and will be "submitting the case to the Summit County Attorney's Office for screening as soon as we complete the investigation."

Hirsch has yet to comment publicly on the incident.

Page Six reports that Bernfeld is a noted Hollywood executive who was chosen to be apart of The Hollywood Reporter's prestigious "Next Gen" list of top entertainment professionals 35 and under for 2014. She has also worked on projects with various stars and producers including Ben Stiller, Elizabeth Banks and Russell Simmons.

Hirsch's appearance at Tao night club on Sunday followed the premiere of his Sundance film "Ten Thousand Saints," Page Six reports.