Foreign Secretary Salman Bashir spoke with the Indian High Commissioner in Islamabad and urged that the singer be released, state-run APP news agency reported.
"Our High Commissioner (in Delhi) spoke with Indian acting Foreign Secretary Vivek Katju this morning again, insisting the protective custody be lifted," APP quoted a statement from the Foreign Office as saying.
There was no official word from the Indian High Commission.
The 37-year-old nephew of legendary Pakistani qawwali singer Nusrat Fateh Ali Khan was detained at Indira Gandhi International Airport yesterday on the charge that he was carrying USD 124,000 that he had not declared.
The Foreign Office is closely monitoring Khan's case and the Pakistani High Commission in New Delhi has set up a special team to liaise with the Directorate of Revenue Intelligence, which has detained the singer.
According to the Foreign Office, Indian authorities have released 12 members of Khan's team but three persons, including the singer, are still being detain, APP reported.
Interior Minister Rehman Malik yesterday asked Pakistan's High Commissioner to New Delhi Shahid Malik to inquire about Khan's detention.