In this paper we consider an interval censorship model in which the endpoin
ts of the censoring intervals are determined by a two stage experiment. In
the first stage the value k of a random integer is selected; in the second
stage the endpoints are determined by a case k interval censorship model. W
e prove the strong consistency in the L-1(mu)-topology of the non-parametri
c maximum likelihood estimate of the underlying survival function for a mea
sure mu which is derived from the distributions of the endpoints. This cons
istency result yields strong consistency for the topologies of weak converg
ence, pointwise convergence and uniform convergence under additional assump
tions. These results improve and generalize existing ones in the literature
.