LAKKI MARWAT, Feb 26: The Government Contractors Association has called upon the district and provincial governments to initiate a probe into alleged use of substandard material in the construction of the district headquarters complex near Tajazai.

Haji Mohammad Zaman, president of the GCA Lakki Marwat, alleged at a press conference here on Sunday that a private construction company was involved in the use of substandard material in the district headquarters complex.