Former RJD MP Rajesh Ranjan, or Pappu Yadav, on Saturday thanked Prime Minister Narendra Modi for conceding to his party's demand for a CBI probe into his arrest and handcuffing earlier this year.

An under secretary in the Union government, Mani Ram wrote to Pappu's JAP(L) saying CBI has been asked to probe, following their memorandum to the PMO.

"Normally, a CBI probe requires state government nod or court direction," a senior high court lawyer said. "But Pappu is a sitting MP and Speaker has asked Centre to probe." But a senior cop speaking on condition of anonymity said: "PMO ordering a CBI probe without state government nod is unprecedented."

"The Delhi Police Establishment Act does not make such a provision. There is no difference made for a case related to an MP or a common man," he further said.