In this work we investigate the complex Leibniz superalgebras with characteristic sequence (n - 1, 1|m1, …, mk) and with nilindex equal to n + m. We prove that such superalgebras with the condition m2 ≠ 0 have nilindex less than n + m. Therefore the complete classification of Leibniz algebras with characteristic sequence (n - 1, 1|m1, …, mk) and with nilindex equal to n + m is reduced to the classification of filiform Leibniz superalgebras of nilindex equal to n + m, which was provided in [3, 7].