Evidence relating to the assisted suicide of the Dublin woman Ms Rosemary Toole Gilhooley will be heard this week in the United States at a hearing attended by gardaí.
A grand jury sitting in West Virginia is expected to hear evidence about e-mails between Ms Gilhooley and local right-to-die advocate, Rev George Exoo.
If the evidence is strong enough, an indictment may be prepared and Rev Exoo and his assistant, Mr Thomas McGurrin, could face extradition to Ireland. Rev Exoo has previously denied assisting in the woman's suicide, but has admitted to being present when the woman ended her life in February in a rented house in Donnybrook.
Gardaí have conducted a long investigation into the death and have examined evidence gathered from Ms Toole Gilhooley's computer and her house.
They have also interviewed several people about the death and liaised closely with the FBI on the matter. Two gardaí travelled to the United States at the weekend and they may give evidence on Wednesday.
Rev Exoo has previously said Ms Toole Gilhooley paid $2,500 in total for expenses for himself and his assistant to pay for hotels, flights and other expenses. He has, however, denied Ms Toole Gilhooley initially contacted him through the Internet.
Earlier this year, the father of the deceased said he bore no ill-will towards the two men who were with her when she died.
Mr Owen Toole said it was "the end of a long, sad story" for his daughter. His daughter was suffering and Mr Exoo "took her gently out of it", Mr Toole said in February. "I give him my full blessing. I still feel I owe him," he said.
He denied a report he had held on to his daughter's suicide note for three days to allow the men to leave the country.
Mr Toole said he contacted the Garda within 10 minutes of receiving the note.
Earlier this year, a US disability rights group called on the state of Virginia to expedite the "expected Irish extradition request" for Rev Exoo and Mr McGurrin.
The group, called Not Dead Yet - The Resistance, based in Illinois, vigorously opposes legal euthanasia and assisted suicides, claiming their legalisation would lead to pressure on the disabled to to take their own lives.
It claimed Dr Exoo lived by "exploiting the desperation of others".
The campaign's president, Ms Diane Coleman, said in a statement released at the time: "Since she reportedly already had enough pills and gas to complete about 20 suicides without any assistance, it looks like what she found in Exoo was someone to agree that she should die and even push her a little.
"As a disabled woman, I see his actions as showing total contempt for her life, and it scares me."