  We present a chemical abundance analysis on the basis of high signal-to-
noise and high resolution spectra for 12 stars of our newly defined sample. The
selection criterion for the stars of this sample was their position in the `RV
Tauri' box in the [12]-[25], [25]-[60] two-colour diagram. An additional
requisite was the presence of a near-IR excess.
  We found that the photospheres of nine stars are affected by the depletion
process. Since the most likely origin of the near-IR excess is a disc, this
strongly suggests that the phenomenon of depletion and the presence of a disc
are linked. Among the depleted stars we find different depletion patterns. In
seven stars elements with a condensation temperature below 1500 K are not or
only slightly affected. Large underabundances are measured only for most
elements with a condensation temperature above 1500 K.
