The Federal Trade Commission (FTC) will probe into Apple's marketing of in-app purchases in games for children such as 'Smurfs' Village', reported the Washington Post.

Acting upon the complaint from the legislator, the FTC sent a letter to Representative Ed Markey of Massachusetts saying that it will look closely at the current industry practice with respect to the marketing and delivery of these types of applications.

We fully share your concern that consumers, particularly children, are unlikely to understand the ramifications of these types of purchases, John Leibowitz, FTC Chairman, wrote. Let me assure you we will look closely at the current industry practice with respect to the marketing and delivery of these types of applications, the Post quoted Leibowitz as saying.

An FTC spokeswoman acknowledged the letter but declined to comment further. Apple did not immediately respond to an interview request.

After the Washington Post first broke this story earlier this month, I sent the Federal Trade Commission a letter calling on the agency to investigate the issue of 'in-app' purchases and provide additional information about the promotion and delivery of these applications to consumers, especially with respect to children, Markey said in a statement. What may appear in these games to be virtual coins and prizes to children result in very real costs to parents. I am pleased that the FTC has responded, and as the use of mobile apps continues to increase, I will continue to actively monitor developments in this important area.

Earlier this month, the Washington Post reported on growing public concerns for and discontent with Apple's in-app purchases. Parents complained about having to pay for accidental in-app buying of their children who did not fully understand what they're doing in the iTunes App Store.

Apple hasn't made any comment on the issue yet.