MOSCOW  - Russia's food safety watchdog said on Monday it suspected Serbia of re-exporting Polish apples and was considering banning all fruit imports from the non-EU country, Russian news agency RIA reported. Russia banned all fruit imports from the European Union as part of a wider embargo imposed in August in retaliation to Western sanctions over Moscow's role in the Ukraine conflict.

"Most likely, the apples are Polish," Yulia Trofimova, spokeswoman for the watchdog, was quoted by RIA as saying.

Trofimova said the ban may be imposed within 10 days unless Serbia responds, adding that it would cover "not only fruits but all plants." Serbia and Russia, traditional allies based on their shared Orthodox Christian faith, signed a free trade agreement in 2000. While Serbia has now set its sights on joining the EU,

it has refused to back the sanctions on Russia. "According to a scrutiny by the Trade Ministry, we have no information that could indicate abuses in terms of re-exports of goods ... to Russia," Stevan Nikcevic, a Trade Ministry official told state-run RTS TV late on Sunday.

Serbia's trade minister, Rasim Ljajic, was quoted by Serbian newspaper Vecernje Novosti as saying authorities would urgently investigate.

"We cannot allow one or two exporters to jeopardise the free-trade agreement with Russia," he said.

He also said authorities would verify the quantities of apples being exported from Serbia.

According to data from Serbia's Chamber of Commerce, Serbian apple exports to Russia since the sanctions row erupted between Russia and the West have risen by 48 percent to 118,000 tons.

Officials from the Serbian Agriculture Ministry declined immediate comment.

"Border customs controls have been stepped up as this is the second time this year that we have suspicions about re-export," Ljajic said.