GVH said prices of ceramic masonry elements have risen "drastically" in the recent period, while there are shortages of some products and, in a number of cases, only the products of a single producer are available.
The authority experts visited brick makers and wholesalers on Wednesday, at the start of the expedited investigation.
A report on the probe will be prepared within a month.
The government has announced a crackdown on suspected price-gouging by building materials sellers while a two-year home renovation subsidy scheme for families with children is underway.