The Justice Department is pursuing court orders to make Apple Inc. help investigators extract data from iPhones in about a dozen undisclosed cases around the country, in disputes similar to the current battle over a terrorist’s locked phone, according to a newly-unsealed court document.

The other phones are evidence in cases where prosecutors have sought, as in the San Bernardino, Calif., terror case, to use an 18th-century law called the All Writs Act to compel the company to help them bypass the passcode security feature of phones that may hold evidence, according to a letter from Apple which was unsealed in Brooklyn federal court Tuesday.

The letter, written last week from an Apple lawyer to a federal judge, lists the locations of those phone cases: Four in Illinois, three in New York, two in California, two in Ohio, and one in Massachusetts.

The letter doesn't describe the specific types of criminal investigations related to those phones, but people familiar with them said they don't involve terrorism cases. The 12 cases remain in a kind of limbo amid the bigger, more confrontational legal duel between the government and the company over an iPhone seized in the terror case in California, these people said.

Law enforcement leaders, however, may cite the existence of the other cases as evidence that the encryption of personal devices has become a serious problem for criminal investigators in a variety of cases and settings. Privacy advocates are likely to seize on the cases’ existence as proof the government aims to go far beyond what prosecutors have called the limited scope of the current public court fight over a locked iPhone used by one of the San Bernardino shooters.