Oil prices have fallen below $60 a barrel, as the shockwaves from the Greek "no" vote push prices further down.
This marks the first time since April that internationally traded Brent crude falls so low, down $1.42 to $58.89 a barrel.
US benchmark West Texas Intermediate is also trading at a three-month low, down to $54.40 a barrel.
Although an oversupply has been weighing down on prices, the situation in Greece has caused prices to dip further to the latest low. David Hufton, of oil broker PVM, told the Financial Times:
Given the uncertainty surrounding Greece and the eurozone and the resulting stock market and euro weakness it is not surprising to see the main oil futures contracts losing value.