We report on extinction measurements of photo-induced Ti3+ centres in titanium oxide gels and gel-based organic-inorganic hybrids. Simultaneous absorption and EPR experiments have been carried out. Despite of an expected heterogeneous origin of the absorption band, the electronic traps population is found pure statistical: it can be characterised by effective extinction coefficients (epsilon) over bar = 780 cm(-1) M-1 (gel) and (epsilon) over bar = 340 cm(-1) M-1 (hybrid) in the maximum of the absorption continua, respectively, at 600 nm and 640 nm. Using these values, an extremely high concentration of long-lived trapped electron exceeding 10(20) cm(-3) has been evidenced in these materials. (c) 2006 Published by Elsevier B.V.