dˈʊɹɹɪŋ ðɪs tˈaɪm, hɪz fˈɑːðɚɹ ɛŋɡˈeɪdʒd tˈuː beɪdʒˈɪŋbˈeɪst lˈɔɪɚz, lˈaɪ hˈiːpɪŋ ænd lˈaɪ kʃəŋbɪŋ, tə dᵻfˈɛnd tˈæn, bˌʌt ðə hˈæŋʒuː pˈʌblɪk sᵻkjˈʊɹɹᵻɾi bjˈʊɹɹoʊ dᵻnˈaɪd pɚmˈɪʃən tʊ ɛŋɡˈeɪdʒ kˈaʊnsəl bɪkˈʌz ðə kˈeɪs ɪnvˈɑːlvd stˈeɪt sˈiːkɹᵻts.
During this time, his father engaged two Beijing-based lawyers, Li Heping and Li Xiongbing, to defend Tan, but the Hangzhou Public Security Bureau denied permission to engage counsel because the case involved state secrets.