Senior Oxfam managers will meet the international development secretary later as the charity deals with a fallout from claims of sexual misconduct by its aid workers.
Penny Mordaunt wants to hear more from Oxfam about allegations its staff used prostitutes in Haiti in 2011.
The Charity Commission called for Oxfam to be "frank" about what it did or did not tell the regulator at the time.
Oxfam has denied any cover-up of the allegations.
Ms Mordaunt has said it must account for the way it handled the claims or it risks losing government funding.
The charity's own investigation led to four people being sacked and three others resigning, including the country director for Haiti.
Michelle Russell, director of investigations at the Charity Commission who will also be part of the talks, told BBC Radio 4's Today programme they had been assured that Oxfam investigated the claims fully.
But she added: "Had the details of what has come out been told to us, we would have dealt with this very differently."
Ahead of the government meeting, Oxfam announced new measures for the prevention and handling of sexual abuse cases.
Oxfam has faced growing criticism of the way it handled the allegations of misconduct by its staff in Haiti, where they were working in the aftermath of the huge earthquake that devastated they country in 2010.
On Sunday, Ms Mordaunt told the BBC's Andrew Marr that Oxfam had failed in its "moral leadership" over the "scandal".
She said Oxfam did "absolutely the wrong thing" by not reporting the detail of the allegations and that no organisation could be a government partner if it did not "have the moral leadership to do the right thing".
She said she was considering whether Oxfam should receive any more funding from the government - which gave it £32m in the last financial year.
Oxfam's chairman of trustees, Caroline Thomson, said the charity's board had appointed a consultant earlier this year to review its culture and working practices, which would now be extended.
"It is not sufficient to be appalled by the behaviour of our former staff - we must and will learn from it and use it as a spur to improvement," she said.