We give an answer to abstract Capelli problem:
Let (G, V) be a multiplicity free finite dimensional representation
of a connected reductive complex Lie group G and G' be its derived
subgroup. Assume that the categorical quotient V//G is one dimensional,
i.e., there exists a polynomial f generating the algebra of G'-invariant
polynomials on V (\C[V]^G' = \C[f]) and such that f \not\in \C[V]^G ).
We prove that the category of regular holonomic D_V-modules invariant
under the action of G is equivalent to the category of graded modules
of finite type over a suitable algebra.