undisclosed
/ˌʌndɪsˈkləʊzd ˌअन्डिस्ˈक्लोज़्ड्/ adj. (used about information, news, etc.) not made known or told to anyone (सूचना, समाचार आदि के लिए प्रयुक्त) ज्ञात नहीं या बताया नहीं गया, अज्ञात; गुप्त, गोपनीय
He was taken to an undisclosed place by the kidnappers.