The 27-year-old man from Bruce, ACT, appeared in the ACT Magistrates Court on Friday afternoon, April 24, after being extradited from NSW earlier in the day.

Bail was not applied for and Vosikata, who stood silently in court, will remain in custody until he reappears in the ACT Magistrates Court on May 8. 

No plea was entered and Vosikata was represented by Legal Aid.

No allegations were detailed in court, but police said earlier they arrested Vosikata on the afternoon of April 23 after a major search involving two helicopters and the police tactical unit.

Ms D'Addario has been described as a beautiful woman who was caught up with a man leading a double life with a family overseas.

Chris Reid and his wife, Kathryn, became friends with Ms D'Addario six years ago when she moved next door to their house in the Canberra suburb of Palmerston.

Mr Reid, who now lives in Brisbane, said Ms D'Addario had been dating Vosikata on and off the past few months before she found out he had a wife and children in Fiji.

"Daniela found out he had a wife and kids back in Fiji ... probably a month ago,” Mr Reid said.  

“When Daniela found out, at this stage, this bloke was living in Daniela's unit, not paying any rent and sending money back to his wife and kids in Fiji.

"She obviously flipped and broke up with him. 

“For whatever reason, they got back together."

Mr Reid said he and his wife "got a bad vibe" from talking to Ms D'Addario about the relationship.

Mr Reid described the 35-year-old Ms D'Addario, who worked as a public servant in Canberra and previously taught at Canberra High School, as "a beautiful girl".

Police have also revealed they are looking for witnesses to a possible disturbance in Bruce on the night of April 19 as part of their investigation.

- With Sydney Morning Herald, Canberra Times and Bay Post