He explained that Polish law, in fact, allows its citizens to serve in a foreign army or other foreign paramilitary formation.
"To do this, it is necessary to obtain the permission of the Minister of Internal Affairs and Administration, and as for former military personnel, [they would need to get] the permission of the Minister of National Defense. At the same time, it is necessary to meet a number of other requirements, for example, to have no criminal record, not have tax arrears and other debts, not to be an active military personnel," the source said.
The violator could face a punishment in the form of imprisonment for up to five years if these requirements are not met, for cases of participation in military operations as part of a foreign armed formation.
"In practice, the overwhelming majority of Polish citizens who are fighting in Ukraine, of course, did not receive any permission, but simply went there at their own peril and risk," the source said.
He specified that it is not possible for the country's authorities to determine even their approximate number.
In March, the Russian Ministry of Defense reported that 13,387 mercenaries had arrived in Ukraine since the beginning of the special military operation, including 2,960 Polish citizens. At that time, 5,962 mercenaries have been confirmed killed, most of them Poles (1,497).
In February, Russian President Vladimir Putin said that the largest number of mercenaries in Ukraine were from Poland.