Falling oil prices pushed US consumer prices into their sharpest monthly drop in six years in December, according to government data released today. 

The Labor Department said its consumer price index fell 0.4% last month, in line with analyst expectations. The CPI had declined by 0.3% in November. 

Energy accounted for all of the fall, the steepest monthly fall since December 2008 amid the financial crisis that triggered the Great Recession.

US energy prices slumped 4.7% from November, reflecting the rapid dive in global crude prices since June that has more than halved their value. Year-over-year, energy prices dived 10.6%, the steepest slide since 2008. 

Petrol prices plunged 9.4% in December, and have shed 22.4% in the second half of the year. Food prices rose 0.3% in December, their largest increase since September. 

Excluding food and energy prices, the so-called "core" CPI was unchanged. 

US inflation has remained well below the Federal Reserve's 2% inflation target as the economy slowly recovers from the deep 2008-2009 recession. 

The CPI rose 0.8% in 2014, the second-weakest annual inflation in 50 years in the US, after a 0.1% rise in 2008. 

"This is notably lower than the 1.3% change for the 12 months ending November," the department said in its report.