Day four of the eight-week federal election campaign saw both leaders of the major parties forced to answer difficult questions off script from their policy announcements.
The Prime Minister has denied any wrongdoing after being named in the so-called Panama Papers.
And opposition leader Bill Shorten faced questions on asylum seeker policy.
Malcolm Turnbull continued his campaign south along the east coast, starting the day in Melbourne at a craft beer brewery.
The plan was to talk about how the brewery would benefit from the government's export trade deals and its youth unemployment plan.
But, instead, he was forced to explain his former directorship at Star Technology Services Limited - a company incorporated by law firm Mossack Fonseca.
The Panama-based firm is central to the leaked Panama Papers, confidential documents which name users of offshore companies implicated in tax avoidance schemes.
The Prime Minister says the story is 20 years old and there is no wrongdoing involved.
"Let me say to you that the company in which you Neville Wran and I were directors was an Australian listed company and had it made any profits which it did not, regrettably, it certainly would have paid tax in Australia. But obviously you haven't studied the accounts of the company concerned."
It's claimed the company made donations to Russian politicians before Mr Turnbull became a director.
But a spokesman for Mr Turnbull says he was not aware of any political donations before or during his time with Star Technology Services.
Mr Turnbull says there has been full disclosure.
"There is nothing new there. The company concerned was a wholly owned subsidiary of a public listed Australian company. So an ASX listed company of which Neville Wran and I were both directors for about two years. So the involvement is very, very well known."
Opposition leader Bill Shorten says the explanation does not go far enough.
"The Panama Papers reveal the great lengths to which some very wealthy individuals and large corporations will go to avoid paying tax. There's very serious matters for Mr Turnbull to answer and I think it is incumbent upon him to do so fully. I do not believe that what he said this morning is a full explanation."
Mr Shorten took the opportunity to celebrate his 49th birthday in the key central Queensland seat of Capricornia, with his wife Chloe making her debut on the trail, by his side.
Students at the Frenchville State School marked the occasion.
Mr Shorten stuck with Labor's education campaign, announcing $1.8 billion of funding for regional schools for 2018 and 2019, if Labor wins office.
But questions turned, instead, to the party's asylum seeker policy, after Immigration Minister Peter Dutton seized on Labor Macarthur candidate Dr Michael Freelander who reportedly called Australia's immigration detention facility in Papua New Guinea a concentration camp.
Labor's federal leadership has vowed to maintain a tough approach to immigration, in line with measures in place under the Coalition government.
Mr Dutton says Labor MPs are now in open revolt.
"Now Mr Shorten wanted to go into this election campaign making Australians believe that the Labor Party was going to be a carbon copy of the Liberal Party when it came to stopping the boats and restoring integrity to border protection in this country. But what has unravelled in the last few days is bigger than any of us estimated. Eighteen, 19, even more I suspect over the coming days, will be identified as those who are adamantly opposed to Mr Shorten's position on boats."
Bill Shorten says the Coalition's claim is without foundation and disunity isn't an issue.
"Well, I don't accept the language that was used at all by our candidate.And let me again state, the Labor's Party has dealt with this difficult issue at our conference last year. Our candidates understand that the issues of the mishandling by the government of regional processing and semi-indefinite detention on Manus and Nauru, that legitimately upsets many Australians. But when it comes to the fight against people smugglers we are 100 per cent determined to stop them plying their evil trade."
Mr Shorten will face off against Malcolm Turnbull in the first leader's debate on Friday in Sydney.
