Vohra, presently working as joint secretary in the external affairs, is expected to take up his assignment shortly, the statement said.
Prime Minister Narendra Modi on Monday attacked Congress president Sonia Gandhi, saying its leaders had no right to talk about tolerance when they were involved in the 1984 anti-Sikh riots.
Congress president Sonia Gandhi will lead her party's protest march to the Rashtrapati Bhavan on Tuesday against "rising intolerance" during the BJP-led government's tenure.
Officials said they had "nothing more to investigate" against them.
A 43-year-old woman has accused an African man, whom she was not able to identify further, of raping her many times on the pretext of marriage and filming objectionable videos
The move follows the controversy around the police investigation into the cases which has led to a deadlock with hardliner Sikh activists and organisations who have rejected the police probe.