Dhar has played in four Tests, 78 One-Day Internationals and 15 T20Is for India and has over 1000 runs and 81 wickets combined but her last appearance for India came in March 2012.
The 34-year-old will join the Indian squad in the rainbow nation for the final three T20Is with India on brink of another series victory having won the first two games.
The decision to include Dhar came after senior fast bowler Jhulan Goswami failed to make sufficient progress from the heel injury that she sustained during the third ODI against the same opposition.
Having already won the ODI series 2-1, India will head into the third T20I in Johannesburg on Sunday with a 2-0 lead following seven and nine wicket wins in Potchefstroom and East London respectively.
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