The video, filmed in 2009 when Mr Rudd was prime minister, was leaked in February last year, further inflaming Labor's leadership tensions. It showed outakes of Mr Rudd recording a message in Mandarin.

It was anonymously uploaded on YouTube on a Saturday evening, soon after one of Mr Rudd's supporters had called on Prime Minister Julia Gillard to stand down.

The AFP investigated the leak last year, and announced it had finalised its work in October.

But concerns were then raised by Mr Rudd that the matter had not been thoroughly investigated.

On Tuesday, the AFP said that while the matter ''remained finalised'', it was ''talking to some additional people who were identified by Mr Rudd as being potential witnesses''.

It is understood these include former staff members of Mr Rudd's in 2009 and staff members of Ms Gillard's in early 2012.

A spokesman for Mr Rudd, who is travelling to the World Economic Forum in Davos, said that the Member for Griffith initially referred the matter for the police last year as it related to a ''possible theft and unauthorised used of Commonwealth information''.

The spokesman said that since the AFP finalised their investigation last year, ''further information has been drawn formally to their attention and as a result it is understood statements have been requested from various individuals to clarify these matters further''.

Last year, Ms Gillard said that her office did not have access to the material that was put on YouTube and that any suggestions her office was connected with the leak were ''completely untrue''.

The secretary of the Department of Prime Minister and Cabinet, Ian Watt, sent a statement to staff last year, saying an internal review showed the video had not come from the department.