Slideshow ( 8 images )

BUENOS AIRES (Reuters) - Six suspected drug traffickers were arrested after 389 kg (858 pounds) of cocaine were found in the Russian embassy in Buenos Aires, a discovery that triggered a joint police operation lasting more than a year, Argentina’s government said on Thursday.

The investigation started in 2016, when the Russian ambassador to Argentina called local authorities to report that traffickers were trying to move 16 bags of cocaine from the Buenos Aires embassy by way of a diplomatic flight.

As part of the unprecedented joint Argentine-Russian police operation, authorities replaced the cocaine with flour while it was still at the embassy.

“A tracking device was placed in the suitcase that was to be used to make the shipment to Russia, which was its destination,” Argentina’s Security Minister Patricia Bullrich told reporters.

The investigation led to the arrest on Wednesday of an Argentine policeman and another citizen of the South American country. Other involved in the scheme had been arrested in Russia, while one of the leaders of the plot was still on the run, Bullrich said.