Three-dimensional arrays of structurally confined InP wire-like nanostructures were grown in channels (nanotubes) of a chrysotile asbestos matrix by metalorganic chemical vapor deposition. The formation of the InP compound was confirmed by absorption spectroscopy, X-ray diffraction and Raman scattering. It is shown that the density of states around the band edge increases with the InP loading of the matrix. Photoluminescence spectra of the asbestos filled in with InP consist mainly of two bands: a high energy band which is interpreted to be associated with charge transfer from InP to defect states of the asbestos and a low energy band which is associated with energy relaxation in the InP deposit itself. We show that the optical properties of this material are dominated by the size and dimensionality of the pore system of the matrix for heavy loading and by the semiconductor-to-matrix interface for light loading of the matrix with InP. ©1997 American Institute of Physics.