Delhi Police have been approached by the Enforcement Directorate to probe into ‘tampering or theft’ of electronic documents seized from the office of businessman Gautam Khaitan, arrested in a money laundering case related to AgustaWestland chopper deal.

It is also alleged that an employee of a private forensic science laboratory was approached by the employees of Khaitan’s office — O P Khaitan & Co. in south Delhi’s Defence Colony — to delete few folders of a laptop’s hard disk containing incriminating documents, sources said on Saturday.

“The tampering was noticed when the seized original hard disk was sent for further probe at a forensic science laboratory in Bangalore. The lab informed ED that the hard disk was empty, but a clone of the hard disk contained incriminating documents due to which it is believed that the data was deleted after the hard disk was seized,” a source told Deccan Herald.

The Delhi Zone office of the ED had conducted raids at Khaitan’s home and office premises on September 22. During search, the laptop of an employee, Manish Jain, was taken for probe and two clones were made of the original hard disk with the help of forensic experts. “The original hard disk was seized and a cloned copy was taken to be used as ‘office-working copy’, and the other cloned copy was given to the employee,” the source added.

The ‘office-working copy’ was examined at ED’s office in central Delhi’s Akbar Road and found to contain large number of incriminating documents. The original hard disk was then sent to the Bangalore office of Truth Labs on September 24 for retrieval of deleted files and emails.

However, on October 3, Truth Labs informed ED that the hard disk contained the default installation of Microsoft Windows operating system and the in-built recovery system, and that no user data was stored. The investigating officers of ED were surprised as the cloned copy contained data, and it was impossible that the original would be blank. “ED believes that the original hard disk has been tampered with,” the source said.

Police have also been informed that a forensic expert of Shree Computers, whose service was used for cloning and examination of seized computers and laptops, was approached by at least two employees of OP Khaitan & Co. to delete a few folders from the `office-working copy’. The forensic expert claimed that he did not assist Khaitan’s employees and informed ED.

The Delhi Zone office of ED had booked Khaitan and others under Prevention of Money Laundering Act on the basis of a Central Bureau of Investigation FIR alleging unethical dealings in the Rs 3,546 crore deal involving the purchase of 12 AgustaWestland helicopters for VVIPs. On the basis of a complaint, Delhi Police have also filed a case under Indian Penal Code and Information Technology Act.