It didn't take long for DISH Network (NASDAQ:DISH) to respond after SoftBank CEO Masayoshi Son called the DISH counteroffer for Sprint Nextel (NYSE:S) "incomplete and illusory."

Today the satellite pay-TV provider filed a letter with the Federal Communications Commission pointing to media reports about a Department of Justice investigation into charges of bribery by telecommunications equipment provider UTStarcom (NASDAQ:UTSI), also known as UTSI. The DOJ says the company gave $7 million to Chinese government officials in return for telecommunications sales contracts. In 2009 UTStarcom admitted to bribery and agreed to pay $1.5 million.

The bribery, a violation of the Foreign Corrupt Practices Act, was alleged to have taken place at least partly during the time that the SoftBank CEO was in charge of UTSI.

"The affiliation between SoftBank and UTSI seems to have been close. Specifically, Mr. Masayoshi Son was Chairman of the Board of UTSI ... [during a period in] which a portion of the conduct in question occurred," DISH wrote in its filing. "Dish believes that this information is relevant to the public interest analysis of the proposed transaction, and that it is incumbent upon the proposed transferee SoftBank to provide a full explanation of these matters."