The Muslim cleric fell into a two-year coma after being shot in the head near his home in northwestern Sweden.
The 37-year-old Russian is suspected of plotting to kill Obid Nazarov, an imam highly critical of the Uzbek regime, who was shot in the head in Strömsund, in northwestern Sweden, four years ago.
Nazarov miraculously survived the attack, but fell into a coma which would last more than two years.
Public broadcaster SVT said the Russian suspect had been detained in absentia in order for authorities to have him extradited from Russia to Sweden to stand trial.
Earlier this week, an appeals court upheld the sentencing of a 37-year-old Uzbek man who had been convicted by a lower court for attempting to kill Nazarov. The court ruled that the attack was a contract killing.
During the court process, Uzbekistan faced accusations of political violence on Swedish soil, the first time a country has been subject to such allegations in the Nordic nation.
The new allegations come as the prosecutor in that case showed that the Russian suspect kept in close phone contact with the Uzbek hitman and that he transferred money into his account.
Nazarov was granted political asylum in Sweden in 2006, after fleeing the Uzbek government's crackdown in Andijan.
After resettling in Sweden, Nazarov began serving as imam in the small Swedish town of Strömsund, with a population of just over 4,000.
A documentary aired by Uzbek state television in May 2010 accused Nazarov of masterminding a series of high-profile killings in 2009, as well as a 2004 suicide bombing at the US embassy.
This article has been updated to clarify that the man has been detained in absentia (häktad).