LUCKNOW, Sept. 20 -- After getting the state government's nod, the Vigilance Establishment has lodged an FIR against the mother-in-law of Samajwadi Party founder Mulayam Singh Yadav's younger son and four other former Lucknow Development Authority (LDA) officials for alleged irregularities in the allotment and registration of plots in the Priyadarshini Yojana of the Jankipuram area in Lucknow between 2010 and 2015, senior vigilance officials confirmed here on Friday. Ambi Bisht, the mother-in-law of the SP founder's younger son, is a former estate officer of the LDA. A senior government official confirmed the vigilance probe, an open inquiry, was ordered into the matter during the Samajwadi Party regime in 2016, but it remained pending for years. He said vigilance officials submitted their report to the state government recently and the FIR was registered after clearance from the government. Inspector Rizwan Abbas of the Vigilance Establishment registered the FIR with Lucknow sector police station of the Vigilance Establishment on Thursday, confirmed senior vigilance officials. According to the FIR, the five former officials have been booked under Indian Penal Code (IPC) section 120-B for criminal conspiracy and section 7 of Prevention of Corruption (PC) Act, 1988. Those named in the FIR include Virendra Singh, former section officer, Devendra Singh Rathore, former deputy secretary, Ambi Bisht, former estate officer, Suresh Vishnu Mahadane, former senior accountant and Shailendra Kumar Gupta, former junior assistant. The complainant mentioned in the FIR that the probe revealed the accused officials used fake documents to calculate plot values and irregularities in plot allotment and registration. He said the forgery was confirmed in the forensic examination of documents. When attempts were made to reach her for her version, Ambi Bisht did not respond to multiple calls made on her phone number. There was no response to messages sent to her WhatsApp number. Her daughter Aparna Yadav, too, refrained from commenting on the issue during a Sultanpur visit when asked by reporters about the FIR lodged against her mother. Aparna is married to Prateek Yadav, the son of late Mulayam Singh Yadav and his second wife, Sadhna Gupta. Ambi Bisht was employed with Lucknow Municipal Corporation (LMC) for a long time and held key positions, including zonal officer. She was in the LDA on deputation. Her husband, Arvind Singh Bisht, is a journalist and has served as an information commissioner. The Priyadarshini-Janakipuram Yojana was an ambitious residential project of the LDA. It was launched in the early 2010s to meet the housing needs of the city's northern part. However, an investigation in 2016 revealed serious irregularities in the allotment of several plots under the scheme....