FBI to probe effort to impersonate top Trump advisor, sources tell CBS

The FBI is investigating an effort by one or more unknown people to access the personal phone of Susie Wiles, the White House chief of staff, sources told the BBC's US news partner CBS.

The key Trump ally told people that her phone had been hacked after a impersonator - or impersonators - used her contacts file to message other top US officials, sources told CBS.

Some recipients of the messages raised suspicions after they were asked if they could continue a conversation in another platform, such as Telegram.

"The White House takes the cybersecurity of all staff very seriously, and this matter continues to be investigated," a White House spokesperson said.

The period of time over which the messages were received is unknown.

The Wall Street Journal first reported the incident and the FBI probe launched in response.

The impersonation was targeted at her personal phone, not government phone, the Wall Street Journal reported. It also reported that the recipients included US senators, governors and top business executives.

Wiles is the first female White House chief of staff and was seen as a key architect of US President Donald Trump's re-election campaign.

It is not the first time she has been at the centre of concerns around cybersecurity.

Last year, three members of a cyber espionage unit associated with Iran's Revolutionary Guards - a powerful branch of Iran's armed forces - were indicted for launching cyber attacks on the Trump campaign team, which Susie Wiles led.

Responding to the latest incident, FBI director Kash Patel said in a statement to CBS News: "The FBI takes all threats against the President, his staff, and our cybersecurity with the utmost seriousness; safeguarding our administration officials' ability to securely communicate to accomplish the President's mission is a top priority."