The Russian Consulate General in Guangzhou issued an advisory last week, warning that border guards at China’s Guangzhou Baiyun International Airport had begun to randomly select Russian travellers to verify their stated purpose for visiting China by searching their smartphones, including photos, videos and messages. Individuals could be blocked from entering China if border officials found compromising information on their phones, the message said.

Russia has requested an official explanation from China over a reported new policy in which Russian citizens’ phones are randomly seized and searched by Chinese border guards.

"We sent the Chinese a detailed note asking them to explain what criteria the new measures are based on," Grigory Kolyshkin, the attache of the consulate general, told the state-run TASS news agency on Tuesday.

"We asked them to provide their criteria for compromising information, grounds for checking phones, whether this is a new policy, and, if so, why it was not communicated in a timely manner," he added.

While the exact number of Russians whose phones had been searched at the Chinese border is unclear, the cellphone searches have only taken place in Guangzhou so far, Kolyshkin said.

“Guangzhou is a kind of hub for tourists,” he said. “We know that in [nearby] Shenzhen, for example, there have been no such [cellphone checks].”

The consulate general will issue further instructions to Russian citizens once it receives a response from China, according to Kolyshkin.

“As soon as we receive a response, we will be able to inform our citizens about the introduction of new measures or their absence,” he said.