Demand for oil from members of the Organisation of Petroleum Exporting Countries (Opec) is expected to keep falling until 2020. The cartel said prices will recover to $70 a barrel at the end of the decade.

The organisation signalled that the oil crisis, which has seen oil benchmark prices plummet to little over a third of what it was in 2014, is not nearing an end any time soon. With Brent crude reaching new lows of near $36 (£24, €33) a barrel, the commodity's costs are a far cry from $115 per barrel in 2014.

"Although lower oil prices continue to foster some demand in growth, their impact seems to be limited by other factors," the cartel said in a statement. "The removal of subsidies and price controls on petroleum products in some countries and ongoing efficiency improvements will all likely continue restricting oil demand growth."

Adjusted for inflation, oil will not reach $95 per barrel until 2040, still well below 2014 levels, Opec estimates. It also sees a slight decline in its own production, which is set to be 1.7 million barrels per day, lower than previously expected, now at 30.7 million bpd. International oil demand is expected to increase by around half a million to 97.4 million per day.

Opec said it was forecasting huge investment cuts and higher exploration costs for the coming years, which will decrease supply. The cartel is expecting to invest some $1tn in new production between now and 2040.