COPENHAGEN, Denmark (AP) — A Russian citizen living in Denmark has been charged with espionage for allegedly having provided information about Danish energy technology, among other things, to an unnamed Russian intelligence service, the Danish prosecution authority said Wednesday.

The suspect, who was not identified, has been held in pre-trial custody since the beginning of July, Denmark's Prosecution Authority said.

The case is based on “a major investigation” by the Danish Security and Intelligence Service, which added that the person had received money in exchange for the information.

If found guilty, the Russian citizen faces up to six years in jail. The prosecution can also seek to have the person deported from Denmark.

The Russian Embassy in Copenhagen identified the suspect as a man and said in a statement that it considers the arrest a mistake and hopes for his acquittal.

“We expect the Danish judiciary to take an unbiased approach to the case,” the Embassy said. “We hope that the court will acquit our citizen and set him free.”

No date has been set for the criminal case, which is is expected to be held behind closed doors. Denmark's TV2 broadcaster said the trial would be held in Aalborg, northern Denmark.

In 2012, Finnish national Timo Kivimaki who was working with the University of Copenhagen as a researcher, was sentenced to four months in prison for spying on Denmark on behalf of Russia.