The way you are going, soon you are going to start asking where does it say you cannot interview a criminal whose name is "Maryam".
First of all, when you interview a criminal, you ARE glorifying them. All criminals do not get that chance. Why anyone particular? Specially when you do not interview them about their crime but everything else.
Secondly, as claimed by you, there is no clause that forbids the interview of a person under investigation.
If Ishaq Dar was not guilty, he would not be an absconder from his own country. He should present his case in court first & then on TV. He is wanted by the state.