Despite the significant improvement in accuracy supervised learning has brought into person re-identification (re-id), the availability of sufficient fully annotated data from concerned camera-views poses a problem for real-life applications. To alleviate the burden of intensive data annotation, one way is to resort to unsupervised methods. This has motivated us to propose a novel algorithm for unsupervised video-based person re-id applications. To achieve this, the frames of a person video tracklet are divided into a set of clusters that are subsequently matched using a distance measure based on the Naive Bayes Nearest Neighbor algorithm and Spearman distance. Knowing that person sequences may suffer from substantial changes in viewpoint, pose and illumination distortions, our technique allows the rejection of poor and noisy clusters while retaining the most discriminative ones for matching. Experiments on three widely used datasets for video person re-id PRID2011, iLIDS-VID and MARS have been carried out, and the results demonstrate the superiority of the proposed approach.