Infrared spectroscopy (FTIR) is a basic tool used in biological sciences to characterise and identify various types of compounds or their mixtures. Lately it is in use also in archaeometry. The FTIR method can be useful for verifying symbolic graves (cenotaphs) or so-called vessels without bones. The a priori interpretation of such remains often raises doubts. The case analysed in the article is a fully preserved face urn discovered in a cist grave on the cemetery at Tuszkowo, Kujawsko-Pomorskie province. The presence of a thin (1 cm) layer of sand on the vessel's bottom might raise doubts concerning actual lack of human remains. To dissolve any doubts, the sediment's sample was analysed using the FTIR technique.