[en] The unique features (super-low background and large sensitive volume) of the CTF and BOREXINO set ups are used in the CAMEO project for a high sensitivity study of ¹⁰⁰Mo and ¹¹⁶Cd neutrinoless 2β decay. Pilot measurements with ¹¹⁶Cd and Monte Carlo simulations show that the sensitivity of the CAMEO experiment (in terms of the half-life limit for 0ν2β decay) is ∼4 x 10²⁴ yr with a 1 kg source of ¹⁰⁰Mo and ∼10²⁶ yr with ∼100 kg of enriched ¹¹⁶CdWO₄ crystals placed in the liquid scintillator of the CTF. The last value corresponds to a limit on the neutrino mass of m_ν ≤0.06 eV. Similarly with 1000 kg of ¹¹⁶CdWO₄ crystals located in the BOREXINO apparatus the neutrino mass limit can be pushed down to m_ν ≤0.02 eV. (orig.)