AI system · finance, internal audit and investigation of improper spending
Financial audit with local AI
REKA Group · 2025 · AI system · Python, Microsoft Presidio
Auditing a large body of documents without data going outside: conversion, anonymisation, RAG analysis on local models
A project to detect misuse of a corporate group’s funds: a body of documents (about 3.9 GB in Markdown) is processed locally or on secure servers. The work produced a study of LLMs and GPU infrastructure, a final “quality vs. time” scenario on a single H200 GPU with Qwen2.5-72B and two-tier escalation (a small model picks out suspicious items, a large one does the detailed analysis), a cost estimate and a roadmap. Tools were built for conversion to Markdown, reversible anonymisation of personal data and RAG analysis on Milvus; a trial analysis was carried out with a final report.
The task
To establish where, when and why the money was spent, without passing confidential data to external services.
What’s inside
- Conversion of PDF, DOCX, XLSX and other formats to Markdown
- Reversible anonymisation (Presidio, spaCy NER, Faker): full names, organisations, phone numbers, emails, dates, amounts, INN, SNILS, OGRN, bank accounts, cards, IBAN; realistic substitution and placeholder modes, date shifting, amount scaling, a mapping table for de-anonymisation
- RAG analysis of related documents (contracts, invoices, payment orders, letters, completion certificates) and a graph of entities and transactions with anomaly detection rules
- An air-gapped mode for working without external APIs; reports in Markdown, JSON and Excel
Machine translation — being proofread.