"It has been very frustrating," Lonergan said. "We have written to them but they haven't responded [to offers]. All they keep saying is 'we want more time' because they are pursuing TV and sponsorship deals in France. They want to hold the fight up there."
If the sides cannot reach agreement as seems probable now - Duco would obviously prefer the fight to be in New Zealand - the IBF will put the fight to a purse bid which effectively opens it up to the highest bidder.
Such a means of deciding negotiations isn't unusual in boxing - the details for the Martin v Vyacheslav Glazkov fight for the vacant IBF heavyweight title in Brooklyn were settled by purse bid.
Martin's promoters won the bid and the American southpaw won the fight and the title by TKO after Glazkov retired hurt with a knee injury.
The undefeated Parker, who has fought 18 times as a professional, is at his Las Vegas base training for the bout against the 35-year-old Takam, who has a 33-2-1 professional record and will be the biggest test of the South Aucklander's career.
Parker said recently there was an element of risk for both himself and Great Britain's Joshua in their next fights.
"Most fighters take little steps at a time and I think at this stage me and Joshua have taken a big step for both our next fights," he said.
"It's a step we need to take, because there is a lot of interest in what we're doing in our careers in the heavyweight division."