New Delhi: The Central Bureau of Investigation (CBI) on Tuesday sought 10-day police custody of Delhi Chief Arvind Kejriwal's Principal Secretary Rajendra Kumar and four others in connection with a corruption case to the tune of Rs 50 crore.

Producing Kumar and other co-accused before the Patiala House Court, the CBI informed that the Principal Secretary was not cooperating during the interrogation.

The investigating agency further said their custody was needed to investigate the money trail.

The court, however, questioned the CBI if the case was registered in December 2015 then what was the need tio arrest Kumar now?

To which the CBI replied: "Kumar is a highly placed bureaucrat and a fair investigation cannot be done if he intimidates witnesses in the case.

The CBI claimed that Kumar intimidated witnesses.

"He holds such a high position that he can influence witnesses and witnesses that is why his custody is needed," the CBI told the court.

The CBI further said they also need to confront with other accused and relevant documents in this regard and that is why they are seeking 10-day police custody of Kumar and four other accused.

Kumar and others arrested by the CBI on Monday evening.

According to CBI sources, Kumar has been charged with abusing his official position to award contracts to M/s Endeavour Systems Pvt. Ltd. and securing government tenders worth Rs. 9.5 crore between 2007 and 2014 for the company.

Kumar has been booked under Section 120-B of the Indian Penal Code (IPC) and under the provisions of the Prevention of Corruption Act.

CBI sources said Kumar emerged as the kingpin of the 50 crore scam, which first started activity in 2006.

The CBI had in December last raided Kumar's office at the Delhi Secretariat in this connection.

Kumar had moved an appeal before a special court in March this year seeking the release of his laptop, iPad and cash seized by the CBI.

A trial court had in April also ordered the de-freezing of two bank accounts of M/s Endeavour Systems Pvt. Ltd.

The Delhi High Court had then stayed the trial court's order allowing for de-freezing of accounts of M/s Endeavour Systems Pvt. Ltd.