Data from a desktop computer was midway through a transfer when Mamata Banerjee walked into I-PAC’s Salt Lake office on Thursday morning, Enforcement Directorate (ED) sources said.

The chief minister was cordial in her interaction, while ED personnel present at the site were allegedly “overawed” by her sudden appearance. The transfer process, according to the sources, came to a halt.

Soon after, Mamata was allegedly in possession of the data, and left the office much as she had entered, multiple ED sources said on Friday.

According to a report the ED is said to have sent to its headquarters, the visiting team had just identified what it believed were the most crucial computers among several machines at the 11th-floor I-PAC office in Sector V when the raid was interrupted.

On Thursday, Mamata entered the I-PAC office at the Godrej Waterside building in Sector V around noon and stayed for over four hours. She was accompanied by bureaucrats and police officers, led by Bengal DGP Rajeev Kumar, who allegedly formed a protective ring around her.

The chief minister left the office at 4.22pm, minutes after I-PAC head Pratik Jain arrived. The ED team remained inside for nearly two more hours and exited the premises around 6.45pm.

CRPF personnel escorted the ED officials out of the building amid slogans from irate Trinamool Congress supporters who had gathered outside.

Explaining the technical process involved, a senior ED official said: “Before transferring material from a computer, generating a hash value — a unique string of characters that identifies digital data — using an algorithm takes time for forensic experts. Any slight change in the value affects the data transfer. If the process is impeded midway, the transfer stops entirely.”

On Friday, two senior ED officers — heading separate teams at Jain’s Loudon Street residence and the Sector V I-PAC office — independently submitted incident reports detailing Thursday’s raids and the subsequent developments to the ED headquarters.

“The reports have been emailed to headquarters. Nothing more,” a senior ED official in Calcutta said.

According to ED sources, senior officers at Pravartan Bhawan in Delhi, including special directors and additional directors, will scrutinise the reports before placing them before the top leadership. A consolidated report, based on the two independent submissions from Calcutta, will then be submitted to the revenue department under the Union ministry of finance.

Loudon Street

Sources within the central agency said the team at Jain’s Loudon Street residence had intended to take possession of a laptop and a mobile phone that Mamata allegedly took away while leaving the premises on Thursday morning.

“The team, led by an assistant director, was so overawed upon spotting the chief minister inside a raid venue that no one possibly dared to stop her,” an ED official said, adding that senior IPS officers were present at both locations.

Meanwhile, a section of senior Kolkata Police officers alleged on Friday that when a team from Shakespeare Sarani police station reached Jain’s residence and sought details of those inside the premises and personnel deployed outside, they were stonewalled.

“A sergeant was denied entry when he reached the address to enquire about what was happening inside. Even officers of the rank of deputy commissioner were not allowed access. This led to a heated exchange between CRPF personnel and their counterparts from Kolkata Police,” one officer said.

Within minutes of the verbal confrontation, the chief minister arrived at the Loudon Street address. Kolkata Police Commissioner Manoj Verma had reached the spot a few minutes earlier, sources said.

While Mamata left the premises within minutes of entering, the ED team remained inside for at least three more hours and exited the address around 3pm.