Bougainville's chief referendum officer, Mauricio Claudio, says just a fraction of the funding promised by the Papua New Guinea national government has been received.
Mr Claudio works for the Bougainville Referendum Commission and said they are running out of time to complete their work for the vote which begins on 12 October.
The writs are due on 16 August.
The National Government had promised a total of $US7.8 million dollars to fund the commission's work, but Mr Claudio says just $US2.25 million has been put in its bank account so far.
He said, despite the hold ups, the commission is committed to delivering the referendum as scheduled.
"It is ultimately for the governments to decide the date of the referendum, the BRC can only advise the governments on whether to go ahead or not, but for now the BRC is committed to delivering those dates. Of course those dates were premised on the timely receipt of sufficient funding, which has not, to date, been fulfilled."