(9) Where any person is charged with having in his or her possession or conveying in any manner milk which it is suspected has been sold or offered for sale and declares that they purchased or received the same from some other person, or that he or she was employed as a carrier, agent, or servant, or to convey the same for some other person, the court is authorised, if practicable, to cause every such other person, and also, if necessary, every farmer, or other person through whose possession such milk has passed, to be brought before it and to examine witnesses upon oath touching the same, and if it appears to the court that any such person has had possession of such milk, every such person shall be deemed to have had possession of such milk at the time and place when and where the same was found or seized, and he or she is liable to punishment accordingly.