Abstract from the article "We'll do away with the spies, saboteur and wreckers!"

…Finnish communists that work in Karelian Soviets created the Karelian jäger brigade. Due to the lack of vigilance, the commanding posts in this brigade occupied so called "political emigres" from Finland. Finnish gendarmerie artificially created such a situation as if this "communists" were victimized and arranged their escapes through the border. Some of them entered the Infantry Commanding School named after Sklyansky and later were sent to the the Karelian brigade. By the ideas of Finnish secret service the Karelian jäger brigade should have become the first Finnish armed body in the Soviet territory during the war, with the aims to organize the anti-Soviet revolt, to paralyze the Kirovskaya railway, to block the Red Army from the North, to cut off Karelia and Kola Peninsula and to prepare the background for the occupation army. At the same time on the territory of Karelia some counterrevolutionary elements were organized into underground nationalist groups that should act as a reserve during the war.

In other words, if the spies-provocateurs continue to stay in the Karelian jäger brigade they could do a lot of trouble in the first days of the war, during the first days of the mobilization. This actions were done by the Finnish secret service by the recommendations of the German General Staff. But our Soviet intelligence unmasked and smashed this spies wasp nest in the Karelian jäger brigade.

Leonid Zakovsky¹
The article from the collected articles "Some methods and ways of the foreign secret servises and their Trotskist-Bukharinists agents", Partizdat Of the Central Committee of C.P.S.U.(B.), 1937.

¹ The head of the Leningrad and Leningrad region department of NKVD (People's Commissariat of Internal Affairs), 1st grade Commissar of the National Safety. real name – Hienrich Shtubis (many of the old bolsheviks used their "underground" nicknames after revolution). Shot in August 29th 1938 as a German and Polish spy and a member of Trotskists organization.