The International Development Secretary is to meet with the National Crime Agency following the Haiti sex workers scandal.
Speaking about the scandal surrounding Oxfam, Penny Mordaunt said: “While investigations have to be completed and any potential criminal prosecuted accordingly, what is clear is that the culture that allowed this to happen needs to change and it needs to change now.”
She said she would meet with the body on Thursday following a week of talks with charity bosses, regulators and experts.
Charities receiving UK aid have been told to show “full transparency” and outline assurances about their safeguarding process.
“If our standards are not met, then the British taxpayer will not continue to fund them,” Ms Mordaunt said.
The comments come following claims some of Oxfam’s aid workers used prostitutes in Haiti following the 2010 earthquake.
Speaking in Stockholm, the minister issued a stern warning to the charity that its Government funding could be at risk over its handling of the allegations.
She said it was “not solely the actions perpetrated” by Oxfam workers but “the way the organisation responded”. She said the crackdown should be a “wake-up call” to the aid sector.
Ms Mordaunt added: “No organisation is too big, or our work with them too complex, for me to hesitate to remove funding from them if we cannot trust them to put the beneficiaries of aid first.”
Officials from Oxfam are due to meet with the Charity Commission on Wednesday.