Go to MRP
Click View/Print Results By Part
Enter a From Part and To Part, the former can be entered on its own to select a single part only
Use the options in the Part dropdown menu to view the demand for the part, these will display either Purchase Order, Sub-Contract, Other, or all demand
The Type column defines what kind of event generated the demand (e.g. A Master Schedule)
The Caused By column indicates the specific order which caused the demand
Looking at the source indicator, if it is prefixed by yy it is a system and not demand generated requirement. So this is likely to be a safety stock requirement which is against the part record, also check to see if the part has stock location policies set as this will also impact.
If this does not work go to Stock and open up the Part List, select the part you are interested in, left click to select the line and in the view section on the menu bar, select Predicted Free. Keep the defaults and save. That will show your outgoings and incomings with a running balance.
Further information can be gained from a Special Report, select the part on the list, Home and then preview, that gives you part details and also a wide variety of other reports that you can use such as Last MRP Results.
The purchasing control desk could be showing demand for parts linked to completed works orders. This would be caused by orphaned kit records that had not been properly marked as completed when their parent works orders were closed. Contact support to get assistance to get them set correctly.