SAP GTS: Legal Control: Purchase order XXX is locked

Hi Guru,

Our distribution personnel are trying to perform a stock transfer from 123 to 234  This is their message:

I ve have not seen this before, this is a stock transfer from 123 to 234 getting the GTS error.

SAP GTS: Legal Control: Purchase order XXX is locked.

Which transaction code I should use, I tried in GTS legal control import data blocked and put the PO number but it's showing no data found. Please suggest.

Thanks