Kathmandu, February 9 The Commission for the Investigation of Abuse of Authority has impounded files relating to Hilton Hotel, which is  under construction in Naxal. A source at Kathmandu Metropolitan City Office said it provided the files to the CIAA yesterday. The CIAA had shown serious concern about the quality and legality of the under-construction infrastructure of the hotel after a portion of a road caved in on January 7. The Naxal Bhagwati temple-Balmandir road section had caved in, opening a cavity measuring around 25 metres deep on January 8. The road section caved in allegedly due to extensive digging at the construction site of the proposed five star hotel. Traffic has been affected along the stretch since. CIAA officials and KMC engineers inspected the construction site. Earlier, the Good Governance and Monitoring Committee of the Parliament had alleged that the KMC had issued building permit for the hotel sans necessary study. Jagdamba Hospitality has the construction contract.