“The Russian side insists on the immediate release of Andrei Zamiyatnin,” the Russian foreign ministry said in a statement, referring to the 29-year-old research student due to be indicted Thursday.
“The conduct of the Swedish authorities in this affair will not fail to have an impact on overall Russian-Swedish relations,” it added.
Zamiyatnin faces a six-year jail term if convicted of what authorities describe as spying activities that threatened Swedish defence. He denies the charges.
He was arrested on February 15 in Uppsala, north of Stockholm. He was researching botany and plant viruses at the town’s University of Agricultural Sciences.
Swedish public prosecutor Tomas Lindstrand said Zamiyatnin had been engaged in spying activities since January 2005. Zamiyatnin was under surveillance for several months by the Swedish security agency Säpo.
A Stockholm court extended his original period of detention by two weeks on March 3. He is due to be indicted on Thursday.