  We investigate the profinite completions of a certain family of groups acting
on trees. It turns out that for some of the groups considered, the completions
coincide with the closures of the groups in the full group of tree
automorphisms. However, we introduce an infinite series of groups for which
that is not so, and describe the kernels of natural homomorphisms of the
profinite completions onto the aforementioned closures of respective groups.
