  We predict an unconventional background free signal of the Higgs boson in
$R$-parity violating nonminimal supersymmetric models at the Large Hadron
Collider (LHC). The signal comprises dilepton plus four hadronic jets and two
large displaced vertices. The displaced leptons and jets are coming from the
decay of the lightest supersymmetric particle (LSP), which is predominantly a
gauge-singlet neutrino. A pair of such LSPs can couple to a Higgs boson,
created via gluon fusion. We have analyzed two cases - one corresponding to the
tree-level Higgs boson mass and another with the one-loop corrected mass of the
Higgs boson. A reliable Higgs mass reconstruction using this signal can lead to
discovery at the LHC with center-of-mass energy $\sqrt{s}=14~\rm{TeV}$ and 5
fb$^{-1}$ of integrated luminosity $(\mathcal{L})$. Even at
$\sqrt{s}=7~\rm{TeV}$ and $\mathcal{L}$ = 5 fb$^{-1}$, a reasonable number of
events are expected. Besides, mass reconstruction of a gauge-singlet LSP can
provide an estimate of the seesaw scale.
