The initial investigation into two airspace violations last Thursday has concluded that the planes involved were Russian SU-27 fighter jets. The first violation occurred at 16:42 on 6 October, with the second breach coming on the same day at 21:33.
The report found that the planes flew in Finnish airspace for around 13 kilometres, going 1.2 kilometres and then 1.9 kilometres over the frontier.
The details found by the border guard tally with what the Defence Ministry found in the immediate aftermath of the incidents. The report found that the movements of the Russian planes could not be reasonably explained by weather conditions or other aviation traffic.
The report was not tasked with finding out why the planes moved into the skies above Finland. The two fighter jets were both intercepted and escorted by Finnish planes scrambled to respond.
The breaches were significant because other airspace violations in recent years have been by cargo planes, rather than fighter jets. On the same day as the Russian planes crossed the line, Finland signed a defence co-operation agreement with the United States.
Russia's Defence Ministry has previously denied both airspace violations.
The border guard has previously investigated an incident in June in which a Danish helicopter strayed into Finnish airspace over the southern coast.