Bill Shorten's leadership ballot under scrutiny

The vote that installed Bill Shorten as Labor's federal leader has been called into question.

An ALP tribunal has found that ballot papers of at least 20 ALP members were redirected to the mailing address of a disgraced councillor from Sydney who has been suspended from the Labor Party for six months over accusations of branch stacking.

That councillor, Hicham Zraika, from Auburn, never alerted party officials when the ballot papers arrived in his mailbox, according to Fairfax Media.

"If in fact he had no prior knowledge of the change in address, the arrival of more than 20 ballot papers must have been quite alarming," said the tribunal.

"It required positive action both because it was necessary to preserve the integrity of the [federal Labor] leadership ballot and it was also necessary to ensure that all other ALP correspondence was sent to the correct address."

The mailing addresses were altered at the request of a staff member of senator Sam Dastyari, Farifax Media said.

At the national ballot to elect Labor's federal leader in October 2013, rank and file members and federal labor MPs were each given 50 per cent of the vote.

Shorten lost the rank and file vote but won the caucus vote to defeat Anthony Albanese by 52 percent to 48 percent.