During her stay at Castle Seeon, Knopf reported that Tschaikovsky was actually a Polish factory worker called Franziska Schanzkowska. Schanzkowska had worked in a munitions factory during World War I when, shortly after her fiancé had been killed at the front, a grenade fell out of her hand and exploded. She had been injured in the head, and a foreman was killed in front of her. She became apathetic and depressed, was declared insane on 19 September 1916, and spent time in two lunatic asylums. In early 1920, she was reported missing from her Berlin lodgings, and since then had not been seen or heard from by her family. In May 1927, Franziska's brother Felix Schanzkowski was introduced to Tschaikovsky at a local inn in Wasserburg near Castle Seeon. Leuchtenberg's son, Dmitri, was completely certain that Tschaikovsky was an impostor and that she was recognized by Felix as his sister, but Leuchtenberg's daughter, Natalie, remained convinced of Tschaikovsky's authenticity. Leuchtenberg himself was ambivalent. According to one account, initially Felix declared that Tschaikovsky was his sister Franziska, but the affidavit he signed spoke only of a "strong resemblance", highlighted physical differences, and said she did not recognize him. Years later, Felix's family said that he knew Tschaikovsky was his sister, but he had chosen to leave her to her new life, which was far more comfortable than any alternative.