New Delhi: The Delhi Police recorded statements of 16 Rau IAS Study Circle employees as part of its investigation into the death of three civil services aspirants in the flooded basement of the training centre, officials said on Wednesday.

They said that the statements of teachers, directors and security and cleaning personnel have been taken in the last two days.

A police officer said MCD officials, who have been asked to join the investigation, are yet to bring relevant documents regarding sludge removal and actions taken in the past.

City officials will be reminded because they have not joined the investigation, police said.

Of Rau's 16 IAS employees, a test series officer at the institute recorded his statement on Wednesday.

While speaking to him, the manager said that he made the first call to the police control room shortly after the water entered the building.

"I was standing on the ground floor when the road was flooded after the rain. The door broke after the SUV drove through the flooded street, causing water to swell and enter the basement," the employee said.

He said the accumulation of water was not new in that lane, but that day it was an unexpected situation.

"We all helped the students in their rescue operation, but it was very unfortunate that we lost our three students," he said.

On the issue of the "illegal" library located in the basement, the director said employees were not aware.

The owner of the carriage had installed iron plates on the front door so that water could not enter the building, he added.

According to a police officer aware of the investigation, police have also recorded statements of some of the surviving students as many of them are yet to come forward.

The officer said the police may question VP Gupta, father-in-law of Rau's IAS owner Abhishek Gupta, again in the coming days.

Meanwhile, the police have called some vendors to record their statements in connection with the case. On Wednesday, two juice sellers were called to the local police station, official sources said.

MCD officials had claimed that they could not carry out desilting or clearing storm drain due to encroachment of vendors in the area.