R-diagonal pairs arising as free off-diagonal compressions

We show that if one takes a free off-diagonal compression of a * -free family of elements in a tracial C * -probability space, then one obtains a free family of R-diagonal pairs, in the sense of Nica and Speicher [4]. The proof relies on the matrix version of the full Fock space model for the R-transform, recently introduced by Shlyakhtenko [6].