No evidence of Tina Greer has been found since she left her daughter, then 13, with a friend in January 2012, planning to visit her partner of six years bikie Lesley "Grumpy" Sharman.
An inquest due to be held next month has been delayed until September.
Solicitor Bill Potts will be asked to provide a statement regarding whether Mr Sharman was his client at the time Ms Greer disappeared in response to a request from Ms Greer's daughter Lili.
He will be asked to include whether Mr Sharman sought advice about the disappearance of Ms Greer and whether there are records or if he has recollections about the matter.
There were references in the brief of evidence that Mr Sharman was speaking to Mr Potts around the time Ms Greer disappeared, solicitor Sheridan Spencer, Lili's representative, said.
One witness said a distressed, crying Mr Sharman told him: "I have seen my solicitor and Pottsy said they're going to charge me; they going to make an example of me because of my connections," Ms Spencer told the court.
Counsel assisting Stephanie Williams said information Ms Spencer initially requested would normally fall within the grounds of legal professional privilege.
"It appears to be on the face of it an attempt at a fishing expedition."
Ms Spencer said she appreciated why legal professional privilege should be protected but Mr Sharman could not be called to give evidence.
"In these circumstances, we have a missing person whose body has never been recovered (and) the main suspect who we suspect was involved in her death has now passed away."
It was one of dozens of submissions by Lili Greer for further evidence to be obtained as part of the coronial investigation discussed at a pre-inquest conference in Brisbane on Thursday.
Coroner Kerrie O'Callaghan refused many, saying some issues could be raised during cross-examination at the hearing.
"I am just trying to make sure that we don't expand this inquest beyond what's really feasible and reasonable."
Ms Greer and Lili moved into a flat at Beechmont on the Gold Coast hinterland in December 2011.
She told Lili she was trying to break up with Mr Sharman as she was sick of his abuse and knew neither of them were safe.
On January 18, 2012 Ms Greer left to visit Mr Sharman on his acreage near Boonah and be back the following day.
She never returned.
Days later her car was found at the Governors Chair lookout at Spicers Gap - a dead end road passing Mr Sharman's house.
No evidence of Ms Greer has been found, but police advised in 2015 she was believed dead.
Mr Sharman, who died in 2018, told police the couple had a stable, non-violent relationship and she left his property alive.
No further useful evidence has been found since police offered a $250,000 reward.
The coroner will consider the police response to allegations of domestic violence, their investigation into Ms Greer's disappearance and investigations into the disappearance of missing women who were known to be domestic violence victims.
It will also consider the response by the Gold Coast-based rehabilitation centre run by the Salvation Army to Ms Greer's disclosures of domestic violence.
The five-day inquest is due to start on September 13.
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