I got the solution:
Set TSTestFact = objTests.TSTestFactory
Set TestSetTestsList = TSTestFact.NewList("")
For Each objTestInst In TestSetTestsList
strTestStatus = objTestInst.Status
strExecDate = objTestInst.Field("TC_EXEC_DATE")
Set iLink = objTestInst
Set bugLinkF = iLink.BugLinkFactory
Set links = bugLinkF.NewList("")
For Each lnk In links
With lnk
Set TargetObj = .TargetEntity
defectID = CStr(TargetObj.ID)
End With
Next
Next
Set TSTestFact = objTests.TSTestFactory
Set TestSetTestsList = TSTestFact.NewList("")
For Each objTestInst In TestSetTestsList
strTestStatus = objTestInst.Status
strExecDate = objTestInst.Field("TC_EXEC_DATE")
Set iLink = objTestInst
Set bugLinkF = iLink.BugLinkFactory
Set links = bugLinkF.NewList("")
For Each lnk In links
With lnk
Set TargetObj = .TargetEntity
defectID = CStr(TargetObj.ID)
End With
Next
Next