Samoa's Central Bank says escalating oil prices pushed the September inflation rate up to eleven point seven per cent.
Inflation in August was ten point four per cent.
The opposition Samoa Democratic United Party said the real cause of the rise in the inflation rate is the government's fuel supply system, whereby the supply tender is put up for bid every five years.
The winner becomes the sole supplier for five years, which the SDUP says is uncompetitive and keeps prices high.
But Ministry of Finance CEO, Hinauri Petana, says the present tender system ensures that local fuel prices reflect market prices precisely.
Petana defends the supply system while announcing new wholesale price increases for fuel for this month.
He says high as current prices are, Samoa's fuel costs remain among the lowest in the region.