Sexual exploitation and abuse is “endemic” across the international aid sector, MPs have warned.

In a report published on Tuesday, the Commons International Development Committee said the sector had been aware of the problem for years but “collectively failed” to prevent it.

The scandal erupted in February after Oxfam was was accused of orchestrating a cover-up of abuse by its staff in Haiti following the 2010 earthquake.

Last month the charity was banned from the country by its government in the wake of the revelations.

Stephen Twigg, the Labour chairman of the committee, said today despite this, there had been an “abject failure” on the part of aid charities to stamp out abuse.

“This horror must be confronted,” he said. “Victims and whistleblowers must not end up feeling penalised for speaking out.”

In its report, the committee concluded: “Sexual exploitation and abuse is ultimately an abuse of power and the aid sector is one of extreme power imbalance: those receiving aid in humanitarian crisis situations are some of the most vulnerable and disempowered people in the world.

“The sector as a whole needs to confront the fact that, although the exact scale remains unknown, sexual exploitation and abuse is happening and it is happening across organisations, countries and institutions. It is endemic, and it has been for a long time.”

Caroline Thomson, the Oxfam Chair of Trustees, said the committee report was “incredibly painful reading” for the charity.

“Oxfam exists to help improve the lives of the world’s most vulnerable people; we know we failed to protect vulnerable women in Haiti, and we accept we should have reported more clearly at the time – for that we are truly sorry. We have made improvements since 2011 but recognise we have further to go,” she said.

In early July the Charity Commission reported it had received 1,152 reports of sexual abuse in the aid sector since the Oxfam scandal broke.

Penny Mordaunt, the international development secretary, has claimed her department’s move to crack-down on abuse has led to “predatory individuals” leaving charities. 

She will hold a global summit in London in October designed to fight sexual abuse in the aid sector.