A search is presented for massive long-lived particles, in the 20–60 $${\mathrm {Ge V\!/}c^2}$$ mass range with lifetimes between 5 and 100 $$\mathrm{ps}$$ . The dataset used corresponds to 0.62 $$ \text{ fb }^{-1}$$ of proton-proton collision data collected by the LHCb detector at $$\sqrt{s} =7\mathrm {\,Te V} $$ . The particles are assumed to be pair-produced by the decay of a Higgs-like boson with mass between 80 and 140 $${\mathrm {Ge V\!/}c^2}$$ . No excess above the background expectation is observed and limits are set on the production cross-section as a function of the long-lived particle mass and lifetime and of the Higgs-like boson mass.