Brent crude futures fell by $1.12, or 1.9%, to $57.82 per barrel on Wednesday, according to trading data from the ICE exchange in London.
The last time Brent crude futures fell below the $58 per barrel mark was in January.
US West Texas Intermediate futures also took a tumble, falling 38 cents, or 0.7 percent, to $53.25 per barrel, in Wednesday trading.
Brent dipped more than 10% last week after US President Donald Trump announced that he would impose 10% tariffs on $300 billion worth of Chinese imports from 1 September, with the decision sending global share prices falling. Beijing responded to the new restrictions on Monday, asking Chinese state companies to stop agricultural imports from the US. China also blasted President Trump's claim that Beijing was acting as a currency manipulator, saying the president's allegations threatened to undermine the global financial order and "bring turmoil to the financial market".
Oil prices have been falling steadily since 1 August. On Monday, Brent fell below the $60 per barrel mark for the first time in six weeks, and on Tuesday it fell below $59 per barrel for the first time since 14 January.
The fall comes after a brief spike in prices in mid-June following a series of sabotage attacks on oil tankers in the Gulf of Oman, with traders speculating over supply concerns. An estimated one third of all sea-bound crude oil travels through the nearby Strait of Hormuz, with tensions in the region escalating between Iran on one side and the US, the UK and other regional powers on the other over a series of tanker attacks, drone shoot downs, and ship seizures.