FRANKFURT/PRAGUE, Dec 26 (Reuters) - The Yamal-Europe pipeline that usually delivers Russian gas to Western Europe was sending the fuel back to Poland for a sixth straight day on Sunday, according to data from German network operator Gascade.

Data showed that flows at the Mallnow metering point on the German-Polish border were going east into Poland at an hourly volume of nearly 1.2 million kilowatt hours (kWh/h) on Sunday and were expected to stay at these levels during the day.

Gascade is owned by WIGA, a joint venture of Gazprom and oil and gas company Wintershall DEA. Wintershall DEA is co-owned by German chemicals group BASF and Russia's LetterOne.

Russia this week said the flow reversal was not a political move, though it coincides with rising tensions between Moscow and the West over Ukraine and has pushed gas prices to record highs.

Russian President Vladimir Putin on Thursday said that Germany was reselling Russian gas to Poland and Ukraine rather than relieving an overheated market, putting blame for the reversal, and rocketing prices, on German gas importers.

Data from Slovak pipeline operator Eustream showed capacity nominations for Sunday's Russian gas flows from Ukraine to Slovakia via the Velke Kapusany border point were at 739,826 megawatt hours (MWh), slightly down from Saturday's 747,031 MWh and below levels in recent weeks. (Reporting by Christoph Steitz and Jan Lopatka Editing by Robert Birsel)