"... is plain and non-compliance renders entry, search and seizure unlawful. Whether or not the property can be admitted in a criminal trial raises quite separate issues."
"Whilst return of the executed warrant to the issuing court is important, especially because of the potential materiality of the warrant for litigation...it would be surprising if a search that met all the statutory conditions applicable at the time it was carried out were to be invalidated retrospectively by a later failure to return the executed warrant to the court. On the face of it, s.15(1) requires the entry and search to comply with s.15 and s.16 in order to be lawful, and does not apply to events that occur after the entry and search have been completed. But even if that is an unduly restrictive reading of the provision, a breach of s.16 will not lead necessarily to the grant of relief ..."