Thanks, Jenny.
Hi Ness, this is a buggy game and many members have reported this problem with the inventory.
A possible reason for items not appearing is if you skip the dialogue at the point when the item should be passed over by the other character. The game blips then and doesn't register that the dialogue took place -- so no item.
Try going back to your last save game, replay this scene, and listen to the dialogue all the way without skipping any.
Another fix which worked for a member at a later stage in the game (with a parcel inside a customs office) is:
Click on your notebook and open the documents tab. The item may be in there. Click on the item and that should put it in the window on the screen as if it had been in the inventory.That might not work for you at this point in the game but it's worth a shot.