Tony Blair could be made to stand trial for war crimes over the invasion of Iraq, Labour leadership frontrunner Jeremy Corbyn has said.
Corbyn said the 2003 conflict was an "illegal war" and that Blair had some decisions he had to "confess".
"Could he be tried for it? Possibly," he told the BBC's Newsnight.
"It was an illegal war... and he [Tony Blair] has to explain to that."
Asked whether Blair should be tried for war crimes, Corbyn said: "If he's committed a war crime, yes. Everyone who's committed a war crime should be.
"I think it was an illegal war, I'm confident about that, indeed (former UN secretary general) Kofi Annan confirmed it was an illegal war, and therefore he has to explain to that."
Pressed on whether he personally wanted to see Blair put on trial, Corbyn said: "I want to see all those that committed war crimes tried for it, and those that made the decisions that went with it."
Last month, Blair angered Corbyn's growing legion of supporters when he suggested that anyone in the party whose heart told them they should vote for the veteran left-winger should "get a transplant".
Corbyn - who is up against Yvette Cooper, Andy Burnham and Liz Kendall in the leadership contest - has emerged as the favourite to succeed Ed Miliband.
The Islington MP has topped a number of opinion polls and his rallies have attracted large numbers of supporters - prompting senior figures to warn against a shift to the left.
The new Labour leader will be chosen on September 12.