LONDON, UK: Chinese hackers have penetrated the White House computer network on multiple occasions, and obtained e-mails between government officials, the Financial Times reported on Thursday, quoting a senior US official.

The cyber attackers managed to penetrate the White House system for brief periods that allowed them to steal information before US government experts each time patched the system, the newspaper reported the official as saying.

The official told the newspaper that US was getting very targeted Chinese attacks so its stretches credulity that these are not directed by government-related organizations.

The US has increased efforts to tackle cyber security in the past year, especially since Chinese hackers penetrated the Pentagon last year, Financial Times said.

In that attack the hackers had obtained e-mails from the system serving Robert Gates, the defence secretary.

While the US has raised concerns about cyber attacks, many foreign governments believe the US is also engaged in electronic spying, the newspaper said. Bob Woodward, the Washington Post reporter had revealed that the US had been spying on the Iraqi government.