The US National Security Agency (NSA), whose controversial surveillance practices are under increasing worldwide scrutiny, awarded a multi-million-dollar contract to computer security solutions provider RSA in order to improve its snooping, according to a Reuters report.

The secretive agency paid $10m (€7.3m, £6.1m) to RSA in order to embed encryption software into a software tool called Bsafe, which is used to secure personal computers and many other products, the news agency said in an exclusive that cited "two sources familiar with the contract".

The contract represented more than a third of the revenue that the RSA division selling Bsafe had taken in the entire previous year, according to the news agency.

In September, the New York Times, citing documents leaked by whistleblower Edward Snowden, reported that the NSA had created and promoted a formula for generating random numbers to create a "back door" in encryption products.

Reuters later reported that RSA helped the agency distribute the formula by embedding it in Bsafe.

RSA Refutes Allegations

RSA, currently a subsidiary of computer storage giant EMC Corp, is widely regarded as one of the most influential firms in the computer security industry, with a long history of championing privacy and security.

The Snowden disclosures shocked computer security experts. RSA also asked its customers to stop using the NSA formula after the disclosures.

"RSA always acts in the best interest of its customers and under no circumstances does RSA design or enable any back doors in our products. Decisions about the features and functionality of RSA products are our own," the company said in a statement.

Snowden, a former technical contractor for the NSA, leaked details of several top-secret US and British government mass surveillance programmes to the press. He was granted asylum in Russia, damaging the country's relationship with the US.

The documents leaked by Snowden revealed that the NSA has been tapping telephone conversations and spying on the internet activity of citizens, leaders, bureaucrats, businesses and government agencies. The NSA had made use of data from tech giants including Google, Facebook, Apple, AOL and IBM, according to the documents.