Pictured: ‘Civilian internees of a concentration camp in Petrozavodsk returning from their day’s work, April 1942. In reaction to what had proved to be an unhappy choice of terms, the camps were renamed “transit camps” in 1943. Photo: Finnish Defence Forces Photographic Centre SA 83211.’ — Oula Silvennoinen

Quoting Antero Holmila in Finland in World War II: History, Memory, Interpretations, pages 547–8:

Ahto criticized Seppälä, in some respects for a reason, for deliberately leaving a lot of information untold in order to present a warped view on the Finnish occupation of Eastern Karelia. Yet Ahto could have mentioned that Finnish authorities did call their camps concentration camps—no quotation marks needed as Finnish documents habitually used that term. Also, no doubt these camps reeked of death, as Seppälä pointed out. Over 24,000 people were incarcerated in these camps and over 4,200 died.⁸⁸

In an Eastern Karelian population census from April 1942, the death toll in the concentration camps was 137.5 people per 1,000 inmates. In a camp in Petrozavodsk, over 3,000 inmates died during 1942.⁸⁹ All this was documented in Finnish archives but—by and large—not considered worth examination.

As Antti Kujala recently remarked about examining the killings of the Soviet prisoners‐of‐war during the war: “Before 1991 it would have been virtually impossible to conduct this kind of research.”⁹⁰ In 1987, as mentioned above, Pietola tried, but the reception was cold. Not least because of his indicting conclusion:

When we are looking for the real reasons for the unusually high death toll of ethnic Russian prisoners‐of‐war and civilians in Finnish prisoner‐of‐war camps and concentration camps […] we cannot bypass the premise that Finns were raised in the spirit of nationalism. With the consolidation of those foundations and fascist ideology, an extreme hatred and contempt against Russians was born.⁹¹

(Emphasis added.)

If anybody is wondering why this information was especially obscure during the short twentieth century, the likeliest reason is that the Finnish ruling class was afraid that its publication would not only worsen relations with the Soviet Union, but also prompt the Soviets to seek reparations. The bourgeoisie’s destruction of the Soviet Union severely reduced the chances of either happening; the neoliberal bourgeoisie expected the Russian Federation to ‘make nice’ with its camp now.