SAN FRANCISCO (BLOOMBERG) - Twitter Inc. has cut off US intelligence agencies from using a key analytics service for surveillance, according to the Wall Street Journal, the latest example of a Silicon Valley company clashing with the government over user privacy.

Twitter said its partner Dataminr sifts through public tweets to sell information to newsrooms and government agencies, but the company has never been authorised to sell that data to intelligence agencies for "surveillance purposes."

The Wall Street Journal said Dataminr had been providing information for surveillance for two years.

US technology companies and the federal government have been sparring over how much data and information the companies should be sharing to battle terrorism and other threats.

Earlier this year, Apple Inc. clashed with the Justice Department over a request for help in unlocking an iPhone used in a December attack. The Justice Department last month said it gained access to the iPhone data without the company's help.

"Dataminr uses public Tweets to sell breaking news alerts to newsrooms and government agencies such as the World Health Organisation, for non-surveillance purposes," Twitter said in a statement.

"We have never authorised Dataminr or any third party to sell data to a government or intelligence agency for surveillance purposes. This is a longstanding Twitter policy, not a new development."

The Wall Street Journal reported that US intelligence agencies got access to Dataminr's service after the agencies' venture capital firm, In-Q-Tel, made an investment in the firm.

After a pilot program arranged by In-Q-Tel ended, Twitter told Dataminr it didn't want to continue the relationship with agencies, the newspaper reported, citing a person familiar with the matter.

In its fight with the Justice Department, Apple resisted being forced to write new software that would make it easier for the Federal Bureau of Investigation to break into the shooter's phone.

Chief Executive Officer Tim Cook said such a move would pose a threat to the privacy of hundreds of millions of iPhone users around the world, arguing that a backdoor of that nature could be exploited by less reputable parties.

Dataminr, founded in 2009, raised US$130 million (S$177 million) last year from investors including Fidelity Management and Research Co. and Goldman Sachs Group Inc. Chief Executive Officer Ted Bailey said at the time that the money would be used to expand into new markets and broaden the company's offerings.