Brent crude oil has fallen 1.5 per cent in afternoon trading, hitting $49.17 a barrel, a new six month low.
Read more: ICE Brent crude oil falls below $50 a barrel
The sharp fall comes as figures showing US oil inventories falling by more than expected last week failed to offset the glut in supply.
Saudi export pricing numbers which showed a boost in demand for Asia also failed to rally prices with supply still heavily outweighing demand.
While there was a brief rally on Wednesday to $50.78 a barrel, prices fell back sharply.
Read more: Oil price rallies on US inventory figures
The black stuff has seen a 53 per cent decline in its price over the last year.
West Texas Intermediate (WTI) also fell 1.68 per cent in afternoon trading to $44.97.