Police discovered the body of 33-year-old Lerch, who appeared on Top Model in Poland twice, after her family lost contact with her for over a week.
Authorities suspect that her husband, Sławomir, 47, shot her before taking his own life at their home near Poznań City on Sunday, September 1.
He was found next to Lerch with self-inflicted gunshot wounds, and a revolver was recovered near the bodies inside the locked home.
SÅ‚awomir, allegedly involved in drug trafficking, had been arrested earlier this year with 30 other suspects after 60kg of drugs were seized from a warehouse. He was released from custody in early August.
Lerch had kept her marriage to SÅ‚awomir private, and it remains unclear whether her death was a murder or part of a suicide pact between the couple.
Her family, concerned after not hearing from her for more than a week, contacted the authorities, leading to the discovery. The investigation into the tragic incident is ongoing.