Iran's Islamic Revolution Guards Corps (IRGC) has arrested Britain's deputy ambassador and other foreign diplomats for "spying" activities, such as collecting soil samples in prohibited areas, the official IRNA news agency reported on Wednesday.

According to a video released by the IRGC Intelligence Organization, the IRGC has identified certain diplomats at foreign embassies, including deputy ambassador Giles Whitaker, accused of "spying" instead of carrying out their diplomatic functions.

The British deputy ambassador had gone to the Shahdad desert (in central Iran) with his family as a tourist, but the recorded images show the diplomat was collecting soil samples in the area, IRNA reported.

Revolutionary Guards' aerospace missile exercises have been conducted in the desert, Reuters reported, citing Iranian state television. 

The footage of Whitaker and his family in central Iran showed him appearing to take ground samples, Reuters reported, citing Iranian state TV. 

"Whitaker was expelled from the city after apologizing (the authorities)," Reuters reported, citing Iranian state television, while the IRGC-affiliated Fars News Agency said he is being expelled from the country.

However, Britain's Foreign Office said in a statement provided to Sky News, "reports of the arrest of a British diplomat in Iran are completely false."

Samuel Heath, spokesperson of the British embassy in Washington, tweeted: "He (Whitaker) is not even posted in Iran anymore!"

Iran also identified Maciej Walczak, a Polish scientist who visited Iran "under the guise of scientific exchanges," as another arrestee, saying he, as a tourist, went to the Shahdad region in Kerman Province, IRNA reported.

He and his companions collected samples of soil, water, rock, salt, and mud from the region near the testing area, according to IRNA.

Another arrestee is the spouse of a cultural advisor of the Austrian embassy, who visited the villages of Damghan city in Semnan Province, and collected samples of the soil of the area, it added.

(With input from agencies)