The Papua New Guinea Supreme Court will decide on Monday whether Prime Minister Peter O'Neill legally took over from Sir Michael Somare in August.
This comes after a last ditch attempt by Mr O'Neill to have the Chief Justice, Sir Salamo Injia, recuse himself from the case.
That action caused a deferral in the Court's decision on Friday.
Additional police were flown in from across PNG to provide extra security for the expected constitutional decision, which could see a return of Sir Michael to the prime ministership.
There were no reports of violence after the surprise adjournment.
Mr O'Neill's lawyer, Philip Ame, presented an application to have Sir Salamo disqualified from delivering the verdict.
Mr Ame presented affidavits from three Port Moresby men, claiming Sir Salamo had met with Sir Michael's son, former cabinet minister Arthur Somare.
The five-man bench announced its decision on whether the Chief Justice will recuse himself, as well as the verdict on Mr O'Neill's election, will be delivered on Monday morning.
Friday's court session marks the third attempt by the O'Neill government to disqualify the chief justice since the constitutional hearings began in late August.
Supporters of Sir Michael launched the constitutional challenge immediately after Mr O'Neill's August the 2nd election, when MPs votes 70 to 24 to dump Sir Michael and replace him with Mr O'Neill.
Sir Michael's supporters argue there was no vacancy in the prime ministership despite a four-month absence by the 76-year-old political veteran, who had been recovering from heart surgery in Singapore.
As the drama unfolded in the courts on Friday, the Speaker of PNG's parliament, Jeffery Nape, led a vote to ensure Sir Michael remains dumped from his East Sepik seat.
Sir Michael lost his seat in September for missing three sessions of parliament while he was in Singapore, but that has also been challenged in the courts by Sir Michael's supporters, who say he only missed two sessions without leave and was granted permission to miss a May session.
That challenge has been rolled into the main constitutional case.
However, parliament voted on Friday to rescind the May leave order on the grounds Sir Michael did not fully disclose the nature of his illness.