This sounds like efflouresence. It is very common on brickwork, especially in the first 4 or 5 years of construction. It is actually produced by the lime leeching out of the mortar, which then dries on the bricks and make them look whitish. You can clean it off with a weak brick acid mix (available from your local builders merchant), but it may (probably will) come back. It will stop of its own accord eventually, but may take a couple of years.