Reuters are reporting that Japan in January paid nearly twice as much for LNG derived from US shale gas as it did for its cheapest imports.
Japan received 211 237 t of US LNG at an average cost of US$645 a t.
By contrast, the lowest it paid was US$337 a t for 64 246 t of LNG from Angola.
The country paid an average of US$386 a t for all 8.3 million t of LNG it imported last month.
The 428 626 t of LNG imported from Brunei, at US$416 per t, were the second highest-priced supplies.
Australia was Japan's biggest supplier in January, sending 2.01 million t at a cost of US$384 a t.
The US supplies came from Cheniere Energy Inc's Sabine Pass LNG Terminal in Louisiana, the first of several export facilities being built to capitalise on the surge of shale gas supply extracted through new drilling techniques in the past decade.
After the March 2011 Fukushima nuclear disaster led to the shutdown of the country's reactors, Japan's utilities imported record amounts of LNG. The companies later signed up to buy millions of t a year of US LNG.