Evidence of the coexistence of an ordered antiferromagnetic and a spin glass state is given by studying a polycrystalline Tb2CuIn3 Sample with neutron diffraction in a non-magnetic and a magnetic environment. Tb2CuIn3 is an antiferromagnet with competing exchange interactions (J(1) > 0 for nearest neighbours and J(2) < 0 for next nearest neighbours) and an ordering temperature T-N = 33 +/-+/- 1 K. Powder diffraction measurements reveal a broad diffuse peak - due to short-range magnetic order - underneath the (100) long-range order magnetic Bragg reflection. The exposure of the sample in magnetic fields up to 7.5 T, under both zero field and field-cooled conditions, show that neither the long-range magnetic order nor the short-range order are destroyed by the outer magnetic fields. The almost field independent behaviour of the magnetic intensities is explained by the existence of a spin glass state. Support on the simultaneous presence of antiferromagnetic and spin glass states is given by recent ac-dc magnetic measurements. The infinite range model for spin glasses with strong uniaxial anisotropy has predicted this kind of magnetic behaviour.