The mother of a woman who disappeared in regional Western Australia 25 years ago said it was frustrating to witness former bikie associates shedding little light during the inquest into her suspected death.

Lisa Govan was last seen outside the Club Deroes headquarters in Kalgoorlie in the state's Goldfields on the morning of October 8, 1999.

The 28-year-old had been out partying the night before and went to the bikie clubhouse to continue drinking with several others.

She was last seen at about 7:30am walking back into the compound with bikie member Andrew Edhouse and associate Trefor Atkinson, where the two men lived.

Her body has never been found, despite a $1 million police reward.

Mr Edhouse was arrested once and Mr Atkinson three times, but the pair were never charged.

The six-day inquest into Ms Govan's suspected death will not hear from Mr Edhouse because police couldn't find him.

Mr Atkinson appeared on Wednesday.

The words "I can't remember" or "don't recall" have been commonplace in the first three days of the hearing.

Coroner Michael Jenkin told the court it was bikie lore for members or associates to not speak to authorities.

Mother's disgust

Ms Govan's mother Pat said she was frustrated by the lack of a response from some witnesses.

"I was disgusted."

The inquest heard CCTV footage showed Mr Atkinson attempting to or actually striking Ms Govan in the neck outside the Safari Night Club at about 4:30am on October 8.

"I'm not proud. I could very well [have hit her] and I apologise for that," Mr Atkinson said.

The court heard the hostility hadn't lingered because Ms Govan and Mr Atkinson shared a taxi back to the clubhouse.

He was questioned about the accusation that later in the morning he watched Mr Edhouse stomp on the head of an unconscious woman who lay inside the Club Deroes headquarters.

"Did you see Andrew Edhouse kick or stomp Lisa?" Counsel assisting the coroner Sue Markham asked.

"No," Mr Atkinson said.

"Did she leave the clubhouse alive?" Mr Markham said.

"I assume so," he said.

Witness 'untruthful', court told

Mr Atkinson told the court the first time he heard of the incident, which he described as "horrific," was in media reports on Monday.

Counsel representing WA Police, Gemma Mullins, told the court the details were read out to him during two police interviews in 2017 and 2018.

"It's the type of story that would stick in your mind because it's quite graphic," Ms Mullins told the court.

"You are entitled to that opinion," Mr Atkinson said.

Code of silence

Mr Atkinson told the inquest he and Mr Edhouse never discussed Ms Govan's disappearance in the 25 years since she was last seen, despite both being arrested and living together in 1999.

The comment was met with laughter by some in the court, and Coroner Jenkin said he found the response difficult to believe.

"If you're a patched member or an associate of the Club Deroes, the rule is you don't talk to police, you don't talk to anyone," Coroner Jenkin put to Mr Atkinson.

"It's a good idea not to, yes," Mr Atkinson replied.

The inquest also heard from tradesman, Kevin Smith, who was not an associate, but was good friends with many Club Deroes members, including one of the bosses at that time.

His former employee Ross Edwards told the court Mr Smith witnessed Mr Edhouse jump on the woman's head as he stood at the front door of the clubhouse on October 8 and said they needed to get their story straight.

Mr Smith told the inquest on Wednesday that was "definitely untrue".

The details on the incident came after the court heard the clubhouse was not searched by police until six days after Ms Govan went missing.

Police found gaming machines had been moved, a section of the floor repainted and part of the carpet removed.

Partner linked to rival group

Two women at the Deroes clubhouse on that night told the inquest Ms Govan's partner at the time, Tim Hammel, was linked to rival bikie group the Gypsy Jokers.

"At that time, it was sort of an unspoken rule that if you're a girlfriend of a different club member, you don't go to the opposition clubhouse, especially alone," Cecily Evelyn Richards told the court.

Ms Richards and another woman Rana-Tui Torbett said they overheard Ms Govan tell people if her partner knew she was at the clubhouse he'd "kill" her.

"He sort of had friends in the other gang, the Jokers, so it was probably not a good place to be seen," Ms Torbett told the inquest.

The court heard Mr Hammel was on night shift on October 7 and rode around town on his motorcycle trying to find her after his shift ended.

Police were unable to find Mr Hammel to serve him with a summons for the hearing.