New Delhi, Aug. 1 -- Two senior officers of Delhi's central prisons have been asked to join an investigation into an alleged extortion racket inside Rohini jail, officials said on Friday. The Anti-Corruption Branch (ACB) has arrested 11 people, including seven jail officials, for allegedly extorting undertrial prisoners and harassing their families for favours. On July 16, the ACB arrested two wardens for taking a bribe from an inmate's family. Investigators said complaints suggested the two demanded Rs.50,000 to Rs.1 lakh from families in return for basic facilities and preferential treatment. "We have found that the warders, along with an assistant superintendent, were reporting to two senior deputy superintendents," a senior ACB official...