The directorate general of GST intelligence (DGGI) for the first time arrested a Chennai-based woman mastermind, running the racket of fake invoices to fraudulently claim input tax credit on the seventh day of its nationwide drive against the goods and services tax (GST) frauds, officials said. The Chennai zonal unit of DGGI arrested the women as she was running a web of seven fake companies created and operated by herself in the names of her family members, including her recently deceased mother-in-law, relatives and friends, two officials with direct knowledge of the matter said requesting anonymity. “A case was booked against her firm for availing and passing on fraudulent input tax credit (ITC) of Rs 14.87 crore on the companies’ fake invoices,” one of the officials said.