Flights costing more than £5,000 were taken by board members at a part Government-funded development agency, a report by the National Audit Office has revealed.
Seventy percent of the Private Infrastructure Development Group's (PIDG) funding is from the Department for International Development (DfID), which was found to have "not ensured sufficient monitoring and transparency of PIDG administrative costs", according to the report.
The PIDG, a multilateral organisation that invests in infrastructure projects in developing countries, has revised its travel policy after some of its board members were found to have made the large expense claims.
The report said that 15 flights were booked from 2011, each costing more than £5,000.
The National Audit Office (NAO) said PIDG has not regularly published or monitored its total administrative and operational costs, estimated to be around £23.8 million in 2012.
"The NAO considers that DfID's decisions to invest in PIDG have sometimes been based on insufficient analysis and scrutiny, and is concerned that DfID lacks sufficiently robust information to demonstrate
that investment in PIDG is the best option," the report found.
The Government had provided £414 million to the group, which has funded a steel foundry in Nigeria and a hydropower plant in Uganda, as of last December.
Margaret Hodge, chairwoman of the Commons Public Accounts Committee, said the DfID "should get a grip on administrative costs like this".
She told the BBC: "It's outrageous that 15 flights were booked from 2011, each costing over £5,000."
Amyas Morse, head of the NAO, said: "The Private Infrastructure Development Group is providing important benefits to poor people in difficult environments, but DfID does not have enough good evidence to show that funding PIDG is the best option."
A DfID spokesman: "The NAO has recognised that we are already improving the group's operations to drive even more job-creating private investment into developing economies, which is the only sustainable way to end dependency on aid.
"Since 2012 we have agreed new financial controls including value for money rules which restrict business class travel and ensure funds are only committed when projects are ready."