A note on power residue difference sets

In this paper, using Gauss sums, Jacobi sums and the similar argument as in [U. Ott, Sharply flag-transitive projective planes and power residue difference sets, J. Algebra 276 (2004) 663-673], we prove a result on power residue difference sets in a finite field, which implies that the proof of the main results of Ott [U. Ott, Sharply flag-transitive projective planes and power residue difference sets, J. Algebra 276 (2004) 663-673] is incorrect.