Bengaluru, May 6 (PTI): IT major Wipro today said it has augmented security measures at all its office locations after receiving a "threatening letter from an unidentified source".

"Wipro confirms that it has filed a complaint with the local law enforcement authorities after receiving a threatening letter from an unidentified source," Wipro said ina statement.

Wipro has augmented security measures at allits office locations, it said.

"There is no impact on the company'soperations. We have no further comments as the investigation is ongoing," it added.

The company did not specify the nature of the threat.

However, police confirmed reports that someone sent an e-mail demanding Rs 500 crore in digital currency of bitcoins, and threatened to attack Wipro offices with Ricin (a natural toxin found in seeds of the castor oil plant) on failing to do so.

Additional Commissioner of Police (Crime) S Ravi told PTI that a complaint has been registered at the cyber crime police station and investigations are on.

According to media reports, in the e-mail sent on Friday, the sender asked the company to make the payment in 20 days and provided a link for the same.