Full-colour holography is the most perfect imaging technique known to science. The image is essentially indistinguishable from the object. Holograms of human tissue may be examined under a microscope in the same way as a tissue sample, without need for biopsy, and can resolve detail of cell nuclei. The technology required to realise colour holoendoscopy has only recently been developed. Today the appropriate laser sources, polarisation-maintaining fibre optics and recording media exist to construct a prototype full-colour holoendoscope. This project brings together experts from holography, fibre optics, biomedical instruments and medicine to develop a functional prototype device and to analyse its effectiveness in several clinical roles. This technology is expected to have many diagnostic applications, particularly the early detection of gastric, duodenal and colonic cancerous lesions.