( CNET ) -- Investigators for the Department of Justice began asking questions about Apple 's business practices involving digital music at least three weeks ago , multiple music industry sources told CNET . DOJ investigators have interviewed numerous executives at record companies and digital music stores and according to those with knowledge of the discussions , it is clear that investigators are interested in learning whether Apple has employed anticompetitive tactics . The sources said that the department 's inquiry is just in a fact-finding stage and that there is nothing to indicate investigators have found any wrongdoing or would file a complaint against Apple . Representatives from Apple and the Justice Department did not respond to interview requests . This is what we know about the investigation so far . • DOJ investigators have interviewed executives from the four major music labels and several digital music retailers about how Apple wields its iTunes influence . • Part of what investigators are interested in is whether Apple used its market dominance to discourage two of the top record companies from participating in a special Amazon music promotion called the `` MP3 Daily Deal . '' • Apple has a history of throwing its weight around the music sector . Apple 's iTunes accounts for 70 percent of all digital song sales and wields huge power . Apple has often used that clout to dictate terms to suppliers -- that is , the major labels . Here are just a few examples : The major labels wanted variable pricing on songs and albums and for years Apple resisted . In 2005 , Apple CEO Steve Jobs said the top recording companies were `` getting greedy '' after music execs considered a music price hike . Last year , Apple finally gave the labels some additional control over song pricing . The big record companies wanted the ability to sell albums that were unbundled , meaning they wanted Apple to sell hot LPs as a full package and refrain from selling individual songs from these works . Again , on this issue Apple has n't given much ground . To iTunes ' fans , Apple was a freedom fighter . The perception was that Apple was standing up for consumers . Apple 's refusal to force customers to buy full albums saved them from having to shell out money for songs they did n't want . To them , Apple 's reluctance to raise the 99 cent song price was another way the company kept music costs down . And the government never made a peep about these practices . Deal or no deal ? But what may not seem as consumer-friendly is the accusation that Apple tried to squash a competitor 's effort to offer discounted music . Amazon 's `` MP3 Daily Deal , '' is a promotion that involves slashing prices on specific music titles and pushing them heavily on the day of their release . Amazon sometimes negotiated to get exclusive access to the music for a period of time , and the labels and their artists would often support the Daily Deal by promoting it on their Web sites . Apple managers informed the labels that any music included in Amazon 's promotion would receive no promotion at iTunes , music industry sources told CNET in April . In one case , Apple complained to Sony Music Entertainment after seeing material from Alicia Keys touted as part of the Daily Deal . In March , Ed Christman , from Billboard magazine , broke the news about Apple 's attempts to make the labels `` rethink '' their support for the Daily Deal . He wrote that Apple contacted EMI executives with similar gripes about such albums as Corinne Bailey Rae 's `` The Sea , '' Lady Antebellum 's `` Need You Now , '' and Ke $ ha 's `` Animal . '' When it comes to tracing iTunes ' potential DOJ troubles , one has to start with Apple 's success . During the last decade , with its iPod digital music players and iTunes music store , the company completely remade the way people across the globe listen to , store , and buy music . Apple 's iTunes store accounted for 28 percent of all music purchased by U.S. consumers in the first quarter of this year , research firm NPD Group said Wednesday . Two years ago during the same period , iTunes ' market share was 19 percent . Companies that dominate a market as much as Apple rules digital music often are accused of anti-trust violations . When companies are up against similar-sized competitors , then aggressive tactics are seen as just good business . But the same practices from players holding hefty market share can raise eyebrows in a hurry . One other thing . During the same period that Apple saw double-digit growth , Amazon also was grabbing greater market share in digital music . Amazon 's share grew from 6.8 percent in the first half of 2008 to 11.8 percent in the first quarter of 2010 . What DOJ investigators must be asking now is how much did the `` Daily Deal '' help propel that growth and did any of Apple 's actions slow it down ? © 2010 CBS Interactive Inc. All rights reserved . CNET , CNET.com and the CNET logo are registered trademarks of CBS Interactive Inc. Used by permission .
Department . of Justice is asking questions about Apple 's business practices . Investigators want to know whether Apple has employed anticompetitive tactics . Apple 's iTunes accounts for 70 percent of all digital song sales .