The disclosure relates to a plant of the genus Papaver that comprises one or more genomic modifications in multiple genes encoding codeine 3-O-demethylase (CODM) and which do not express detectable codeine 3-O-demethylase activity wherein said modified plant is further modified in one or more thebaine 6-O-demethylase genes (T6ODM) to reduce or abrogate thebaine 6-O-demethylase activity said plant is characterised by increased thebaine content when compared to an unmodified plant of the same species.
