The risk of contamination is a generally recognized and intensively researched field of forensic DNA [1–5]. In spite of quality assurance systems, recommendations and regulations, this risk is always present even in routine casework as evidenced by this example from Hungary. In a murder case, buried bodies were discovered and exhumed. The genetic analyses of remains were performed in two different laboratories (A and B). In case of unidentifiable N.N. body the first analysis in “Lab A” used the soft tissues (muscle) from bone sample. Based on the results, the first two opinions of “Lab A” excluded the biological relationship of N.N. with the putative relatives. The subsequent analysis of “Lab B” used the soft tissue parallel to the bone sample from the N.N. body, and the opinion supported the hypothesis of biological (maternal) relationship with high probability (W = 99.999%). We examined and tried to resolve the contradictions presented by the two interpretations, which originate from contamination of the remaining soft tissue.