More than 120 workers for British charities were accused of sexual abuse in the past year alone, sparking fears overseas aid organisations are being are being targeted by paedophiles.
According to the Sunday Times, Oxfam reported 87 incidents last year, Save the Children reported 31 incidents and Christian Aid two.
The British Red Cross said a "small number of cases of harassment" had been reported in the UK.
The news comes after Oxfam workers were accused of using prostitutes in Haiti following the 2010 earthquake.
International development secretary Penny Mordaunt said it was "despicable" that sexual exploitation and abuse existed in the aid sector and threatened to cut funding to charities if they fail to comply with authorities over safeguarding issues.
Mordaunt said she was taking action to make sure charities were "properly regulated" after the allegations.
"With regard to Oxfam and any other organisation that has safeguarding issues, we expect them to cooperate fully with such authorities, and we will cease to fund any organisation that does not," she said.
"I am very clear: we will not work with any organisation that does not live up to the high standards on safeguarding and protection that we require."
Oxfam said it had already taken measures to prevent sexual abuse and misconduct, including the launch of a hotline to report allegations.
The UK-based charity is also facing fresh accusations that its workers used prostitutes in Chad in 2006, the Observer reported.
A senior member of staff, Roland van Hauwermeiren, led the mission in Chad as well as the Oxfam's work in Haiti, but resigned from the charity in 2011.