In Finnish

Telegram from the Finnish Legation in Moscow to the Ministry for Foreign Affairs, September 28, 1940

Commissar Molotov stated on September 27 that they had heard that a secret treaty of alliance or pact exists between Finland and Sweden which is directed against the USSR and is in conflict with Article 3 of the Peace Treaty. I said that I could deny at once the existence of any such agreement. M. Molotov remarked that I was perhaps not au courant with events, but they possessed information. I asked the source of their information. M. Molotov was unwilling to disclose it, but said that hints had been made to the matter in Finland. He also made veiled hints about information received from Sweden. In this connection, M. Molotov said that we were now talking verbally, but that if they brought forward documentary evidence, the matter would become grave.

Paasikivi.

Source: Finland reveals her secret documents on Soviet policy, March 1940—June 1941. Doc. nr. 28. Wilfred Funk, New York 1941.
The book is a verbatim translation of the "Blue-White Book" published by the Foreign Ministry of Finland, 1941.

The contemporary Peoples' Commissariat for Foreign Affairs report on the Paasikivi-Molotov discussion (in Russian).

Finland in the Soviet foreign policy 1939-1940