Joseph Stalin's Soviet Union used the incident as one of the pretexts to justify its eventual military invasion and occupation of Estonia in June 1940.

[2] However, probably because of German or Soviet pressure, Estonian military authorities soon boarded the ship, declared the crew interned, confiscated all the navigation aids and maps and started to dismantle the armaments.

Two Estonian guards at the dock were lured aboard and nonviolently taken prisoner, the lighting in the port was sabotaged and the mooring lines were cut with an axe.

At the mouth of the harbour, the submarine briefly ran aground on a sandbar but quickly managed to get free and escape to the Baltic Sea.

[4] Lieutenant Grudziński intended to seize the maps of a German vessel, as all of the navigational aids of Orzeł, except for a guide of Swedish lighthouses, had been confiscated.

[4] ORP Orzeł was subject to a refit and subsequently brought into service alongside the Royal Navy in the 2nd Submarine Flotilla in mid-January 1940 to patrol the North Sea.

The Soviets demanded to be allowed to establish military bases on Estonian soil and threatened full-scale war if Estonia did not comply with the ultimatum.

Accusations related to the submarine incident served as a political cover for Stalin's actions, since in the secret clauses of the August 1939 German-Soviet Pact Nazi Germany already provided implicit approval for the Soviet takeover of Estonia, Latvia and Finland.

The Orzeł incident was used by Stalin to force the "treaty of defence and mutual assistance" on Estonia, which was signed on 28 September 1939 and allowed the Soviets to establish several military bases on Estonian soil.