Oakland Raiders linebacker Ray-Ray Armstrong is under investigation for allegedly taunting a K-9 police dog before Sunday’s game against the Steelers at Pittsburgh’s Heinz Field.

The news was first reported by WVAE-TV, an ABC affiliate in Pittsburgh.

The incident in question happened in a stadium tunnel between the visiting locker room and the field during a patrol for explosives ahead of Sunday’s kickoff. The Allegheny County Sheriff’s Office said Armstrong lifted his shirt, pounded on his chest and began barking at the dog in a provocative manner.

“The player was leaving the locker room, en route to the field, when he engaged in conduct that was very intimidating and threatening,” chief deputy Kevin Kraus told WVAE.

Taunting a police dog officer is a third-degree felony charge under Pennsylvania state law.

The sheriff’s office has notified both teams and the NFL and obtained surveillance video from the stadium. Charges could be filed by the end of the week, police said.

“Once the officer was able to identify the player, there was no rush to arrest at that point. Obviously there was a football game going on,” Kraus told the network. “We wanted to make sure we got as much information as we could, properly reviewed it and made a sound judgment how we proceed.”

Armstrong, a third-year reserve who played at the University of Miami and Faulkner University, was signed by the St Louis Rams as an undrafted free agent in 2013 before joining Oakland ahead of last season.

Neither the Steelers nor Raiders immediately responded to requests for comment, though Oakland coach Jack Del Rio was dismissive of the allegations during a radio appearance on Tuesday.

“I’ve caught wind of this story. I’m going to put it in the ‘silly’ category,” Del Rio said on SiriusXM NFL Radio. “I think once the facts come to light I don’t think there’s going to be much of an issue. I wouldn’t make too much of it.”