Mitochondrial genetic markers have been extensively used to study phylogenetics and phylogeography of many birds, including Procellariiformes seabirds. Evidence suggests that part of the mitochondrial genome of Procellariiformes, especially albatrosses, is duplicated. None DNA fragment covering the entire duplication was ever obtained. We sequenced the complete mitochondrial genome of a non-albatross Procellariiformes, Puffinus lherminieri (Audubon’s shearwater) using the long-read MinION (ONT) technology. Two mito-genomes were assembled from the same individual, differing by 52 SNPs and in length. The shorter was 19kb-long while the longer was 21 kb, due to the presence of two identical copies of nad6, three tRNA, and two dissimilar copies of the control region. Contrary to albatrosses, cob was not duplicated. We further detected a complex repeated region between the control region and 12S, of undetermined length. Long-read sequencing suggests heteroplasmy and a novel arrangement within the duplicated region indicating a complex evolution of the mitogenome in Procellariiformes