Russia's oil contamination crisis is almost over, Energy Minister Alexander Novak said at an economic forum in St Petersburg on Friday.
The country's average daily oil output dropped this month to a three-year low after contaminated crude clogged its main export route. Contaminated Urals crude was discovered in the Druzhba pipeline to Europe in mid-April.
Following these reports, Poland, Germany, Ukraine and some other countries suspended imports of Russian oil via the Druzhba pipeline.
The problem arose when an unidentified Russian producer contaminated the oil with high levels of organic chloride, which is typically used to boost oil output but which must be separated before shipment as it can destroy refining equipment.
Russia's pipeline monopoly Transneft was investigating the matter. It had earlier said that the contamination which led to the suspension of the oil flows to Europe could be deliberate and that a criminal case was opened.
(With inputs from agencies)