This invention proposes a multimodal detection of video copies. It first extracts independent audio and video fingerprints representing the changes in the content. It then proposes two alternative copy detection strategies. The full-query matching considers that the query video appears entirely in the queried video. The partial-query matching considers that only part of the query appears. Either for the full query or for each subsegment in the partial-query algorithm, the cross-correlation with phase transform is computed between all signature pairs and accumulated to form a fused cross-correlation signal. In the full-query algorithm, the best alignment candidates are retrieved and a normalized scalar product is used to obtain a final matching score. In the partial query, a histogram is created with optimum alignments for each subsegment and only the best ones are considered and further processed as in the full-query. A threshold is used to determine whether a copy exists.