  We show that the neutron diffuse scattering in relaxor ferroelectric
(1-x)PbZn$_{1/3}$Nb$_{2/3}$O$_{3}$ - x PbTiO$_{3}$ (x=0.07) consists of two
components. The first component is strictly elastic but extended in q-space and
grows below 600 K. The second component, that was not reported before for the
(1-x)PbZn$_{1/3}$Nb$_{2/3}$O$_{3}$ - x PbTiO$_{3}$ (x=0.07) relaxor
ferroelectrics, is quasi-elastic with a line-width that has a similar
temperature dependence as the width of the central peak observed by Brillouin
spectroscopy. The temperature dependence of the susceptibility of the
quasi-elastic scattering has a maximum at the ferroelectric transition.
