Forensic investigation is very crucial for identifying quality and safety issues related to food and its product. GC-MS has been used extensively in food analysis, and in the present study, it was used to identify the active constituents of some household spices as well as to detect the adulterants and contaminants which might be present in the samples. Spices used in the present study are black pepper, cumin, fennel, coriander and turmeric. The spice extracts were found to be useful in authenticating the spices by identifying various active constituents of the spices, like piperine, caryophyllene & 3-carene in black pepper; cuminaldehyde & 1,3-methadien-7-al in cumin; anethole & fenchone in fennel; linalool, & geranyl vinyl ether in coriander and turmerone & zingiberene in turmeric. The adulterants detected qualitatively were plant-based adulterants. GC-MS is proved to be an effective tool in detecting plant-based adulterants, microbial contaminants, agrochemical residues as well as industrial and manufacturing waste.