Gaza also said that the companies should provide details of tax waivers and other incentives enjoyed plus gas and explosives contract details. The Joint Committee of the House of Representatives investigating the arbitrary rise of cement prices in the country has asked major producers in the industry to tender documents on cost production to justify the price of cement in the market.The committee resolved to visit the production plants of the companies after going through their books to ascertain the cost of production with a view to determining a fair price of cement for all Nigerians. The Ch…