FRANKFURT, Oct 20 (Reuters) - German crude oil import volumes fell 7.1% in the first eight months of 2021 year-on-year as the COVID-19 pandemic and related lockdowns hit industry, but the bill was up by a third due to higher prices, official data showed on Wednesday. Oil volumes in January through August fell to 51.9 million tonnes from 55.8 million in the same months of 2020, statistics from the BAFA foreign trade office showed. Russia accounted for 34% of Germany’s oil imports in the period, followed by 18.9% from the British and Norwegian North Sea, while imports from members of the Organization of the Petroleum Exporting Countries (OPEC) contributed 16.1%. The rest was shared among other sources including, prominently, the United States and Kazakhstan. Germany spent 21.0 billion euros ($24.45 billion) on crude imports in the period, 32.9% more than a year earlier. Brent crude prices have gained 52% this year, supported by supply cuts made by OPEC and allies, demand recovery after the COVID-19-induced collapse last year and a global coal and gas crunch which has driven a switch to diesel and fuel oil for power generation. In the German January-August statistics, average oil prices paid for each tonne at the national border had been 42.8% higher than a year earlier at 404.56 euros per tonne, BAFA said. ($1 = 0.8587 euros) (Reporting by Vera Eckert; Editing by David Evans)