Officers found the capsule after they were called in to deal with a fight on Monday evening.
The capsule was stolen the previous night after the place where it was buried was vandalized.
It is one of four time-capsules containing relics related to freedom fighters and descriptions of these relics that were buried in Lukiškių Square earlier this year.
The memorial to freedom fighters was to be built in the renovated square by next December, but work has not started yet.