“Polish farmers comply with EU legislation when exporting fruit,” Kopacz told reporters on Wednesday.
Her comments followed a report in the daily "Moskovsky Komsomolets" in which Medvedev suggested Polish apples tend to be "far more chemically modified" than Russian apples.
"Poles export only those apples covered in chemicals and they eat the good ones themselves," Medvedev said on a visit to a farm in the fruit-growing Krasnodar region of Russia.
The visit was reportedly aimed at justifying the destruction of imported foods and their replacement by Russian products.
According to the newspaper, the director of a Krasnodar farm, Yevgeny Yegorov, told Medvedev that Russian apples are superior to imported Polish ones.
"They have a completely different taste. The Poles spray twice as many chemicals on them as we do,” he said.
The war of words escalated later in the afternoon. with Kopacz debunking Medvedev's suggestions.
“I don’t really want to comment on this. But I know one thing: Polish farmers can be proud of their apples, strawberries, currants and the EU’s safety regulations which we observe for exports," Kopacz told reporters on a visit to the mid-western city of Kalisz on Wednesday.
On Thursday Russia started to dispose of confiscated food as part of a campaign to discourage illegal smuggling of food into Russia.
On the first anniversary on 5 August of the embargo on food imports from the West to Russia, Putin’s campaign to destroy hundreds of tonnes of smuggled food started with consignments from Poland.
Russian Minister of Agriculture Alexander Tkachev told television channel Rossiya 24 last week that 28 tons of apples and tomatoes from Poland had been burnt.
Despite the embargo border guards often stop large amounts of meat, cheese, fruit, vegetables and other products whose importation is prohibited.
Putin’s decree ordering the food to be destroyed entered into force on Thursday. The ban, currently in place until August 5, 2016, covers a wide range of imports including pork, beef, poultry, fish and seafood, milk and dairy products, fruits, vegetables and nuts. (jh/rk)