This came after five members led by former Premier, Patrick Vasuni boycotted the second round of the premier’s election.
Eight members voted for Mr Mapuli in the absence of the other five members.
There are 13 members in the provincial government.
According to clerk, Mathew Sale, there was an argument in the first round of voting over the nomination form of Mr Mapuli, which he did not sign except his two nominators.
Mr Sale said also there was argument over late submission of nomination form before election which had breached one provision of the standing orders.
As such Mr Sale said the Speaker John Bosamata seeks legal clarification from Parliament and Attorney General Chamber and they advised them to call for fresh elections.
However, Mr Sale said his office advised the AG Chambers that there was no budget to hold election after New Year.
Therefore, he said the AG Chambers had advised them to suspend provision for one clear day before election.
Mr Sale said this led them to call the election last Wednesday where Mr Mapuli was elected unopposed in the absence of the other five members.
He said if the five members, who boycotted the election want to challenge the outcome of the election, they could do that in the High Court.
Meanwhile, Rennell and Bellona province has a new premier.
He is Collin Suatai Singamoa, a former police officer.
Mr Singamoana defeated Kushol Tepuke, his rival in contest for the premier’s post, yesterday.
Rennell and Bellona is the smallest provinces in Solomon Islands.
By EDDIE OSIFELO