Thanks Sanjay
I checked in user_source view. result is
sql> select distinct name,type from user_source;
NAME TYPE
------------------------------ ------------
BODY PACKAGE
SP_LOAD PACKAGE

When I tried to Drop the package I am getting internal errors like "The following errors are in the ALERT file : ORA-00600: internal error code, arguments: [15264], [], [], [], [], [], [], [] ORA-00600: internal error code, arguments: [15264], [], [], [], [], [], [], []".
Any other suggestions??