After he returned to Finland, he was arrested by ValPo, the Finnish national security agency. There was a trial for treason in 1946 because he had joined the German army. After the trial he received a 6 year sentence in January 1947. He went to prison in Turku, but he escaped in June. He was recaptured and went to a different prison. In December 1948, Finnish President Juho Paasikivi gave him a pardon.