Fears of a supply glut popped a rebound in the price of oil on Tuesday, with comments from Iran about higher production and a possible lifting of sanctions piling on further pressure.
West Texas Intermediate (WTI) futures fell as low as $42.63 a barrel—their weakest level since the March 2009 nadir of $42.51—before paring some losses.
Brent crude futures hovered near six-year lows below $53 a barrel, before also paring some losses.
Amrita Sen, chief oil analyst at energy research consultancy Energy Aspects, told CNBC that she expected prices to go lower in the short-term, with Brent dropping to the high $40 level and WTI breaking below the $40 mark.
"It's (trading) positioning and the U.S. dollar that is accentuating the downtrend, for sure," the London-based analyst told CNBC Tuesday.
"This is seasonality as well, we forget, its March, April. This is exactly when oil falls every single year. Sure, we usually come off from $110 down to $90, but this is the time when refineries go into maintenance."
WTI prices have dropped around 60 percent since mid-June last year, and are around 18 percent below the rebound seen in the middle of February, when futures pushed back up to around $53 a barrel.