Vladimir Putin instructed the Chief Military Prosecutor's Office to check how and through whose fault conscript soldiers ended up in Ukraine:

Dmitry Peskov said that before the special operation, on the order of the Russian president, all commanders of units of the Armed Forces were instructed to categorically exclude the involvement of conscripts for any tasks on the territory of Ukraine.

And the president was reported that this directive had been fulfilled.  But it turned out that not completely.