THE cost of filling the average home heating oil tank fell below £200 yesterday as crude oil fell to its lowest price since 2003.

And according to a leading economist, the market has not yet reached the bottom.

The cost of 900 litres of fuel has been steadily dropping over recent months as crude oil prices plummet.

At one point yesterday, some suppliers in Northern Ireland were offering 900 litres of heating oil for £191.

It is welcome news for beleaguered householders who were paying an average of £590 to fill a tank as recently as February 2013.

Chief economist at Ulster Bank in Northern Ireland, Richard Ramsey, said prices could fall further still.

"At the moment, it is very good news for the consumer," he said.

"The lifting of sanctions in Iran is increasing the glut in oil supply so we probably haven't got to the bottom yet."

But Mr Ramsey said that while it was obviously good news for consumers, there were several "cautionary notes" to be made.

"What follows low oil prices is much higher oil prices. That's because in the short term there will be less investment in the way we access oil leading to greater costs later," he said.

And he warned lower heating costs, combined with other falls in essential items, could lead to rising costs elsewhere - including taxes.

"When the cost of living is low, it is more palatable for government to raise taxes.

"I think that we will see rises in the March budget.

"It also means companies could be likely to pass on lower pay rises to staff."

The boss of BP Bob Dudley yesterday admitted crude oil prices - currently around $30 a barrel - could fall to as low as $10 a barrel.

The falling prices have made oil by far the cheapest heating fuel type for householders in the north.

It is likely also to have an affect on electricity tariffs, which are currently being reviewed by Northern Ireland's supplier Power NI.

Natural gas tariffs, although falling, have not declined as significantly as oil in the past year.

The cost of wholesale gas makes up just under half of gas bills for households.

That cost has come down marginally in the past year and will likely lead to a small decrease in tariffs when a the current review on charges in the north is complete next month.