The investigation was hampered by difficulties in ascertaining cases, particularly for children who had died.
His own investigation was being hampered by this one.
The investigation has been hampered because central figures have refused to cooperate.
In his reply, he claimed that investigations had not been hampered.
From the start, the investigation has been hampered by the evident defiance of local authorities.
The officer said the investigation was hampered by the fact that most of the witnesses ran out.
The investigation may have been hampered by the clean up operation where victims and debris was removed from the scene.
Any investigation into the savings deductions will be hampered by the passage of time.
On the Senate side the investigation is also being hampered.
The investigation was hampered because witnesses were afraid to speak, in fear of retaliation.