Try Literal Control to embed an iFrame:
LiteralControl litCon = new LiteralControl();
litCon.Text = "<iframe name='testiFrame' id='runtimeIFrame' frameborder='no' scrolling='auto' height='400px' width='100%' src='http://www.google.com' style='left:0; background-color: beige;'></iframe>";
myPanel.Controls.Add(litCon);
Refer:
MSDN: LiteralControl Class[
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