India, Jan. 2 -- It took just one phone call for the Central Bureau of Investigation (CBI) to expose what it describes as a "carefully orchestrated" corruption racket allegedly led by a woman Indian Revenue Service (IRS) officer at the heart of the Central GST department in Jhansi.

That call, made under the watchful eyes of CBI officers, is now the most damning piece of evidence against 2016 batch IRS officer Prabha Bhandari, deputy commissioner, Central GST, accused of masterminding a Rs.1.5-crore bribe deal to bury a major tax evasion case, according to those in the know.

A senior CBI official confirmed the IRS officer was brought to Lucknow, along with her subordinates and others from Jhansi CGST office, to present them before Luckno...