Compared to 1.2 million tonnes for March, just 45,700 tonnes of rail freight were transported by rail from Russia to the Latvian ports of Riga and Ventspils in the first half of May, Meduza reported via Reuters.
The steep drop in freight volume was confirmed by Edgars Sūna, director of the marketing department at Riga port.
Reuters cites sources as saying that Russian Railways, a state-owned railway monopoly is refusing most requests to take cargo from Russia to ports in Latvia.
Sources told Reuters that they suspected the move is a retaliation for Latvia snubbing Nord Stream 2, a Russian-led pipeline project.
While a representative of the Riga Freeport says that Russia might have decided to move its freight through its own ports in Murmansk and Arkhangelsk.
Russian Railways deny that there are any restrictions to sending freight through Latvian ports.
In April the Latvian government turned down Ventspils' involvement in the Nord Stream 2 project citing recommendations by security forces and claiming risks to national security.
Possibility Latvia will lose 'entire Russian transit'
Later on May 24 Sūna told Latvian Radio that the Riga Freeport has seen a steep decrease in freight volumes within the last month and a half.
"In exactly a month and a half the freight volume in freight categories such as coal, petrol and fertilizer has dropped by 45% to 50%," he said.
"We hope that Russia will not be able to reroute freight flows to its own ports, so we'd get a handicap," said Sūna.
"Theoretically there's a chance that we'll lose the entire Russian transit within one, two, or three years. I'm referring to petrol, coal and fertilizer," he said.
Meanwhile Latvian Railways representative Māris Ozols said that the freight volume carried on rail has decreased only marginally. He claimed 2.64 million tonnes have been carried by rail May 1-22, which is 98% in comparison to the same period last year.
Transport Minister denies reports
"There are no decisions, neither official nor unofficial," said Latvia's Transport Minister Uldis Augulis, claiming the reports over the steep decline in rail freight are nothing but rumors.
"They [the media] have cited an anonymous, unknown person who provided this information. [Latvian] Railways have concluded Q1 with a 8.1% growth on year in terms of freight volume and a 29% annual increase for container freight," he said.
He also claimed he doesn't have information about freight reduction from ports as they "aren't really informing" him.
Augulis did however admit that petrol freight volumes continuing to fall.
Russian transit makes up 65% of all freight at Rīga Freeport.