The comments came after more than 70 Parliamentarians signed a letter to Home Secretary Sajid Javid urging the Government to ensure Assange faces Swedish authorities if they request his extradition.
The WikiLeaks founder, 47, is facing rape and sexual assault allegations in Sweden.
Mr Corbyn told Sky News: “If there are allegations which Julian Assange needs to answer of sexual issues, sexual attacks that may or may not have taken place in Sweden, then it’s a matter for the courts to decide.
“But, I do think he should answer those questions.
“My objection was to his extradition to the United States because I do believe that WikiLeaks told us the truth about what was actually happening in Afghanistan and in Iraq.”
The letter to the Home Secretary was organised by Labour MP Stella Creasy and stated: “We are writing to request that you do everything you can to champion action that will ensure Julian Assange can be extradited to Sweden in the event Sweden make an extradition request.
“This would be so the formal investigation into an allegation of rape can be concluded and, if appropriate, a charge can be made and any trial can take place.
“We do not presume guilt, of course, but we believe due process should be followed and the complainant should see justice be done.
“We urge you to stand with the victims of sexual violence and seek to ensure the case against Mr Assange can now be properly investigated.”
The rape allegation has a limitation period which expires in August 2020, it adds.
Assange spent almost seven years in the Ecuadorian embassy in London, where he sought political asylum in 2012 after failing in his legal battle against extradition to Sweden, where he was wanted over two separate allegations, one of rape and one of molestation.
In May 2017, Sweden’s top prosecutor dropped the long-running inquiry into a rape claim against Assange, which he has always denied.
But his arrest prompted the lawyer for a Swedish woman who alleged she was raped by Assange during a visit to Stockholm in 2010 to say they wanted the case reopened.
Prosecutors in Sweden have since confirmed that, while the investigation has not been resumed, they are looking into the case.
Labour MP Stephen Kinnock told the BBC: “Mr Assange is accused of rape and sexual violence in Sweden and it’s vital that that doesn’t get airbrushed out of the conversation because of all the other issues to do with WikiLeaks.
“I think the top priority, as we say in our letter, is to ensure that if the Swedish authorities wish to have him extradited there to face those charges, they must take priority above all else.”
Former Home Secretary Lord Blunkett said people giving Assange “unqualified support” were being “extremely unwise”.
Writing in The Times, the former Labour MP said: “It is indeed important that any extradition hearing should be fair and take into account the mitigation of genuine revelations of wrongdoing made in 2010.
“However, supporting a fair hearing is not the same as a political demand that he should be treated as some kind of hero; he remained in the Ecuadorean embassy to avoid previous extradition hearings concerning claims of rape and abuse in Sweden.
“A kneejerk response that presumes that hacking is acceptable if the perpetrators can claim that their motives were journalistic is particularly dangerous when it emanates from those aspiring to become prime minister or home secretary, such as Jeremy Corbyn and Diane Abbott.”
Shadow foreign secretary Emily Thornberry tweeted: “Why weren’t Swedish authorities told in advance of Assange’s ejection from Ecuadorian embassy, as the US clearly was?
“Our priority should be the 2 alleged victims of sexual violence in Sweden & not a ruse to get him extradited to the US as a whistleblower.”