(1) Subject to the provisions of this section, copyright in any literary, dramatic, musical or artistic work expires at the end of the period of 50 years from the end of the calendar year in which the author dies.
(2) Where the authorship of a work referred to in subsection (1) is unknown, copyright in such work expires at the end of the period of 50 years from the end of the calendar year in which it was first made available to the public; and subsection (1) shall not apply if the identity of the author becomes known after the end of that period.
(3) For the purpose of subsection (2), acts which constitute the making available of a work to the public include—
(a) in relation to a literary, dramatic or musical work, the performance of the work in public or its broadcast or inclusion in a cable programme service;
(b) in relation to an artistic work, the exhibition of the work in public or its inclusion in a film shown to the public or in a broadcast or cable programme,
so, however, that in determining for the purpose of this subsection whether a work has been made available to the public any unauthorised act shall be disregarded.
(4) The provisions of subsections (1) and (2) shall not apply to a computer-generated work, the copyright in which shall expire at the end of the period of 50 years from the end of the calendar year in which the work is made.
(5) In relation to a work of joint ownership—
(a) the reference in subsection (1) to the death of the author shall be construed—
(i) where the identity of all the authors is known, as a reference to the death of the last of them to die,
(ii) where the identity of one or more of the authors is known and the identity of one or more others is not, as a reference to the death of the last of the authors whose identity is known; and
(b) the reference in subsection (2) to the identity of the author becoming known, shall be construed as a reference to the identity of any of them becoming known.
(6) A work is of unknown authorship if the identity of the author is unknown or, in the case of a work of joint authorship, if the identity of none of the authors is known.
(7) The identity of an author shall be regarded as unknown if it is not possible for a person to ascertain his or her identity by reasonable inquiry; but if his or her identity is once known it shall not subsequently be regarded as unknown.