Against the backdrop of Apple’s objection to Amazon’s sale of certain albums exclusively, the US Department of Justice (DOJ) has reportedly initiated early stage investigations to determine whether Apple “unfairly dominates” the digital music arena with its popular iTunes music store.

According to the unnamed sources in the know, the DOJ officials have been trying to get in touch with music labels and other digital music providers, to inquire about the nature of the digital music market, and, in particular, Apple’s role in it.

Going by a New York Times report, the DOJ staffers are questioning digital music companies and labels to check out if Apple has been unfairly exerting its clout in the digital music market and trying to crush Amazon’s bargain music promotions via its Daily Deal program launched nearly two years back.

The inquiry by the DOJ officials has resulted largely from allegations that Apple essentially controls the digital music market – more so as the company’s iTunes store has a nearly 70 percent share of digital music sales and 28 percent of all music sales in the US. Amazon, meanwhile, holds only about 9 percent of the digital music sales.

In addition to the inquiry against Apple in the digital music market, the DOJ officials were also reportedly investigating Apple’s policy towards developers for its iPhone OS platform.