HELSINKI (Reuters) - Finnish police on Thursday arrested a Rwandan man on suspicion of involvement in genocide in Rwanda in 1994.

The arrest followed claims by rights group REDRESS and the International Federation on Human Rights on Tuesday that Finland was one of eight European countries where suspects of Rwandan genocide live.

"The man concerned is suspected of having participated in planning, leading and carrying out the genocide," a police official told Reuters. He did not reveal the man's name.

Thomas Elfgren, detective chief superintendent with the National Bureau of Investigation, said the Rwandan had applied for asylum in Finland in 2003 and the police had been investigating his complicity in the genocide for some months.

Elfgren said the pre-trial investigation would take several months.

The investigation will be carried out with Rwandan judicial authorities and the United Nations International Criminal Tribunal for Rwanda, Elfgren said.

"Even though the investigation was started already at the beginning of the year, our plans were to make the arrest later ... (but) we were forced to act to minimise flight risk," Elfgren said.

He said the man would not be sent to the U.N. court as it operates only until 2008 and is no longer taking new cases. It was not yet decided whether he would face trial in Finland or in Rwanda.