UPDATE 1-Druzhba oil pipeline flows to Poland resume after shutdown -operator

(Adds PERN statement)

MOSCOW/WARSAW, June 20 (Reuters) - Oil flows to Poland through the Druzhba pipeline resumed on Thursday after being suspended on Wednesday evening due to the discovery of contaminated oil, Polish pipeline operator PERN said on Thursday.

Russia suspended west-bound flows through the pipeline in April due to excessive levels of organic chloride in the crude, but PERN confirmed on June 9 that clean oil supplies from Russia had been partially restored.

“This morning, after additional analyses of subsequent batches of crude oil and confirmation of its proper quality, pumping was resumed,” PERN said in a statement, adding there was no threat to supplies for its customers.

Russian pipeline monopoly Transneft also said contaminated oil had been found at a section of the Druzhba pipeline from Belarus to Poland, causing the shutdown on Wednesday, the RBC media portal reported.

PERN said it had asked Belarussian pipeline operator Gomeltransneft for clarification regarding the issue, and was told it was due to switching elements in the system.

Belarusian state oil firm Belneftekhim said on Thursday no new contaminated oil had been found in tests on Belarusian territory and it was looking into PERN’s discovery.

April’s suspension of flows through the Druzhba pipeline affected refiners in Germany, Poland, the Czech Republic, Slovakia, Hungary, Ukraine and Belarus. (Reporting by Elena Fabrichnaya, Maxim Rodionov, Alan Charlish and Anna Wlodarczak-Semczuk; writing by Tom Balmforth; Editing by Jan Harvey and David Evans)