Apparatus for checking tyres in a tyre production line, the apparatus comprising: - a detection system comprising a linear camera having an objective line lying on an optical plane passing through the linear camera; - a first light source, a second light source and a third light source adapted to respectively emit a first, a second and a third light radiation in order to illuminate a linear surface portion of a tyre coinciding with or in proximity to said objective line; - a command and control unit configured for: - selectively activating at least one from among said first light source, second light source and third light source and - activating said linear camera in order to acquire a respective two-dimensional image of said linear surface portion synchronously with the activation of said at least one from among said first light source, second light source and third light source, wherein said first light source and second light source respectively lie on opposite sides with respect to said optical plane, wherein the apparatus comprises a support for said tyre, wherein each of said first light source, second light source and third light source comprises one or more respective sub-sources (111, 112, 113), each having a respective main extension direction which forms, with said optical plane, an angle smaller than or equal to 45° and wherein the distance of said sub-sources of the third light source from said optical plane is less than the distance of said first light source and second light source from said optical plane, wherein said third light source is adapted to illuminate said objective line with diffuse light, wherein said third light source comprises at least four respective sub-sources distributed on both sides of said optical plane, wherein said sub-sources of said third light source are symmetrically distributed with respect to said optical plane, wherein said sub-sources (111, 112, 113) of the first light source, second light source and third light source are arranged along a line (115; 117) on a reference plane orthogonal to the objective line having concavity directed towards the objective line, said sub-sources (111, 112, 113) being equidistant from said objective line or said sub-sources (111, 112, 113) being arranged as a triangle with vertex on the optical plane, and wherein for each point of the objective line, a respective angle having vertex at the point and lying in a reference plane orthogonal to the objective line, and subtended by said third light source, is greater than or equal to 70°. - a detection system comprising a linear camera having an objective line lying on an optical plane passing through the linear camera; - a first light source, a second light source and a third light source adapted to respectively emit a first, a second and a third light radiation in order to illuminate a linear surface portion of a tyre coinciding with or in proximity to said objective line; - a command and control unit configured for: - selectively activating at least one from among said first light source, second light source and third light source and - activating said linear camera in order to acquire a respective two-dimensional image of said linear surface portion synchronously with the activation of said at least one from among said first light source, second light source and third light source,