By Andrei Makhovsky and Vladimir Soldatkin
MINSK/MOSCOW (Reuters) - Clean Russian oil had reached the border with Belarus by midday on Monday, a Russian official said, five days after European refineries suspended imports because of contamination in the Druzhba pipeline.
Poland, Germany, Ukraine, Slovakia and other countries on the network suspended oil imports via the Druzhba pipeline after finding contaminants that can damage refinery equipment.
"As planned, at 1200 (0900 GMT) on April 29 oil... has reached ... the Druzhba pipeline's Unecha border station," Ilya Dzhus, spokesman for Deputy Prime Minister Dmitry Kozak, said in a statement.
Belarus had earlier said that clean Russian oil had yet to reach its borders via the pipeline -- a major source of oil supply across Europe -- after tainted crude prompted several importers to halt flows last week.
State-run oil company Belneftekhim said that Belarusian refineries were still running at reduced capacity, though Moscow had said it would start pumping clean crude through the Druzhba network from Monday.
The Druzhba network supplies refineries as far west as Germany.
Belneftekhim did not respond immediately to a request for comment after the Russian statement on Monday.
Moscow had also said on Friday that it would take two weeks to stabilise supplies across the Druzhba network, which has northern and southern pipeline spurs.
A source with a buyer at the northern Druzhba leg on Monday said that supplies via Adamova Zastava to Poland and Germany were still halted and were not expected to resume in the short term.
Belneftekhim said it was holding talks with Russian oil companies at Russia's Energy Ministry.
The problems arose when an unidentified Russian producer contaminated oil with high levels of organic chloride, which is typically used to boost oil output but which must be separated before shipment to avoid damaging refiners' processing units.
Russia has not offered specifics about how it planned to clean out contaminated oil from the whole network. Druzhba can ship up to 1 million barrels per day, amounting to 1 percent of global crude demand.
Russian Deputy Energy Minister Pavel Sorokin told reporters in Minsk after Friday's talks that one option was to mix clean oil with the contaminated crude.
Another is to transport clean oil by rail tankers, Russian Railways said last week.
Some refineries have turned to supplies through other pipelines, but analysts say those routes have limited capacity.
Czech oil refiner Unipetrol has asked the government to lend it crude from state reserves, with amounts to be discussed at a meeting on Monday.
Russian pipeline monopoly Transneft is investigating the matter, Russian President Vladimir Putin said on Saturday, adding that this could lead to a wider inquiry, possibly including law enforcement agencies.
The pipeline issue has cut off a major supply route for Polish refineries owned by PKN Orlen and Grupa Lotos, as well as plants in Germany owned by Total, Shell, Eni and Rosneft.
(Reporting by Andrey Makhovsky in MINSK, Robert Muleer in PRAGUE, Olga Yagova, Gleb Gorodyankin, Vladimir Soldatkin and Maria Tsvetkova in MOSCOW; writing by Katya Golubkova; Editing by Edmund Blair and David Goodman)