Dalam pembuktian kes pengedaran dadah, pengetahuan dan jagaan/milikan tentang dadah berbahaya tersebut perlu dibuktikan oleh pihak pendakwaan. Walaubagaimanapun, pengetahuan sahaja tanpa jagaan dan kawalan tidak menunjukkan bahawa seseorang itu memiliki dadah tersebut.
Kes PP V MUHAMAD NASIR BIN SHAHARUDDIN & ANOR  2 MLRH 390 Visu Sinnadurai J menyatakan seperti berikut:-
"Possession is not defined in the DDA. However, it is now firmly established that to constitute possession, it is necessary to establish that: (a) the person had knowledge of the drugs; and (b) that the person had some form of control or custody of the drugs. To prove either of these two requirements, the prosecution may either adduce direct evidence or it may rely on the relevant presumptions under s 37 of the DDA." "Two points must, however, be stressed at this stage: (i) that knowledge is only one of the ingredients of the offence of possession. Mere knowledge by itself does not amount to possession. Therefore, even if the prosecution succeeds in establishing knowledge, it must also go a step further and establish control or custody of the drugs by the first accused;.....”
OLEH: Maisarah Norkefli