KENTVILLE, N.S. -- Witnesses at the trial of a well-known Toronto pastor described the religious leader performing a sexual act on a teenage male and walking down a hallway nude during an alcohol-fuelled party at his Nova Scotia trailer in the 1970s.

One witness said he watched Rev. Brent Hawkes perform oral sex on his friend on the floor of his home in the Greenwood, N.S., area during a party sometime in the mid-1970s.

"I couldn't believe it," the man testified in Kentville provincial court Monday at the trial of Hawkes, an influential gay rights advocate who officiated at former NDP leader Jack Layton's state funeral in 2011.

The witness said he knew Hawkes when he was a student and that Hawkes was a basketball coach and teacher at a school in the Annapolis Valley.

He said he was about 16 years old when a group of people went to Hawkes' home. The witness said he remembers only a few things about that night.

"It's not so much what I remember but what after 40 years I've been unable to forget," said the man, dressed in a blue blazer and jeans.

Hawkes took the young man to a small bathroom, and told him that he had been watching him, and was "80 per cent sure I was gay," he said.

"I said 'No, I don't think so. I'm pretty sure I know my orientation'... It was uncomfortable. It was very uncomfortable," the witness said, later telling the defence he felt that Hawkes was hitting on him.

He said they eventually returned to the living room, and he later looked over to see Hawkes performing oral sex on his friend.

Defence lawyer Clayton Ruby appeared to question the witness on the accuracy of his memories of the evening, noting that last year he told police how many people were in the trailer home that night, but he could not recall that on the stand Monday.

"It's not what I remember sir. It's what I cannot forget," the witness said. "After 40 years I'm trying to forget everything I can about that night."

Hawkes, wearing a black suit with a burgundy tie and glasses, sat in the front row of the gallery, listened intently and took notes inside a black notebook during the testimony Monday. Several of his supporters sat in rows behind him.

Hawkes has pleaded not guilty to charges of indecent assault and gross indecency. Nova Scotia's Public Prosecution Service has said the alleged victim was 15 or 16 years old at the time.

Another man testified Monday he was also at the party that night, and alcohol was being consumed.

"Several hours in, we were underway. We were drunk. But it was a weird drunk," the witness said, saying there was a game being played which required clothes to be taken off.

"When you have four or five heterosexual men in their underwear, you know there's something going on."

When asked by the Crown if there were physical acts that happened at the trailer, the witness put his head down for several seconds and replied, "Yes."

He choked back tears as he described engaging in masturbation with another teenage male in a bedroom where two other people were present. However, he said he didn't recall how he came to be in that situation and said he didn't recall Hawkes being in the room.

The witness also testified that he later saw Hawkes go down the hallway of the trailer with another one of his school friends, and that both were nude.

Both witnesses said they never spoke of the party again until police contacted them more than a year ago.

None of the allegations has been proven in court.

Hawkes has maintained his innocence. He issued a statement earlier this year saying: "I want to be crystal clear: I am innocent of these allegations ... The purported events simply did not take place. I will fight, with all that I have, these accusations."

According to the "Support Brent" website, Hawkes attended Mount Allison University in Sackville, N.B., and later moved to the Annapolis Valley from 1973 to 1976.

Hawkes, originally from Bath, N.B., has been the senior pastor at the Metropolitan Community Church of Toronto for 38 years. Considered one of the spiritual leaders of Toronto's gay community, he is also known as a vocal proponent of same-sex marriage, and in 2007 was appointed to the Order of Canada.