The trial has begun for a pair of B.C. brothers accused of a hate crime in an attack on a gay couple two years ago.

Parminder Singh Peter Bassi and his younger brother Ravinder Robbie Bassi are both charged with assault causing bodily harm and they have both pleaded not guilty in a trial that began Tuesday in Vancouver provincial court.

The Bassis are accused of assaulting David Holtzman and his partner Peter Regier outside their downtown Vancouver apartment on June 12, 2010.

Regier took the stand on Monday and said that he and Holtzman arrived at their Keefer Street home after attending a concert and saw a man urinating on the side of the building. He said they told the man to stop.

Regier told the court that the man started yelling and "the recurrence of anti-gay slurs" was "very striking."

He said the man yelled, "What are you two? Are you two faggots?"

Regier testified that he was punched repeatedly and thrown into a wall after his boyfriend replied in the affirmative.

"I was saying, ‘Please stop,'" Regier said, but his attacker didn't listen.

He was taken to hospital, where he was given staples to close up a cut on his head and treated for multiple bruises. His partner was treated at the scene by BC Ambulance.

Surveillance footage taken near the victims' home on the night of the attack shows two men running away from the scene of the beating. They both appear to be smiling.

Defence lawyers are expected to argue that the Bassi brothers cannot be properly identified in the video.

With a report from CTV British Columbia's St. John Alexander