The Ministry of Foreign Affairs and Trade has voiced its frustration over the unsolved killing of a New Zealand woman.
Lynn Howie and her British partner Mark De Salis were murdered as they picnicked on a Libyan beach a year ago. Investigators described the shooting as an execution.
MFat said it was frustrated at the investigation's lack of progress, compounded by the country's unstable political environment.
"The New Zealand Government has consistently called on the relevant authorities to fully investigate the deaths," an MFat spokesman told the Herald on Sunday.
"While we hope that those responsible will be brought to justice we acknowledge the obvious challenges any police investigation in Libya faces, including a very difficult security environment."
Howie and De Salis were killed on January 2 last year near the tourist city Sabratha in what the coroner at an inquest into De Salis' death described as a "totally motiveless killing".
Howie, a 46-year-old health worker from Wellington, was visiting Libya to see where her partner had worked for the past six years, first at an oil and gas company and then at an engineering firm.
They were going to visit the United Kingdom before travelling to New Zealand where they planned to live together.
During De Salis's inquest, Coroner Tom Osborne said both were shot in the back of the head, the BBC reported.
"It seems Mark was working to restore infrastructure in Libya. It was unfortunate he was in the wrong place at the wrong time."
In March, MFat said it had received assurances from Libyan authorities that the deaths would be fully investigated.
But a close associate of De Salis said at the time that even if the authorities knew who was responsible, police might never be able to arrest the killers.
"Even if they knew who the party or the group were, they can't really do anything because everyone's armed here.
"If the police go and arrest somebody, the next day there's a retaliation and all of a sudden some policeman gets kidnapped."
Since despot Muammar Gaddafi was ousted following a popular uprising in 2011, tensions between nationalists and Islamists have stymied attempts to produce a stable government in Libya.