Roger O'Halloran, the chief executive of Palms Australia, said the Australian Volunteers for International Development program ''had got a little bit strangely fat''.

By its own account AusAID's dollar cost for sending volunteers abroad for 12 months has more than doubled from $30,000 to $69,028 since 2004. Some volunteers are paid annual allowances of up to $46,100.

Mr O'Halloran believes if the Department of Foreign Affairs and Trade cut its suit to fit its cloth it should be able to increase the number of volunteers being sent overseas despite the Abbott government's decision to freeze further increases in aid spending.

The government has also flagged rolling AusAID back into DFAT.

Australia is expected to spend more than $58.5 million to send about 1000 volunteers overseas in 2012-2013. This is up from about $20 million in 2004-2005.

Before the election the plan had been to double the number of volunteers by the end of the decade.

AusAID's office of development effectiveness is conducting a review into the Australian Volunteers for International Development program. An AusAID spokesman said it is ''expected to be completed and published by the end of 2013''.

AusAID refused to comment on a range of issues raised by Fairfax. They included: why it paid program partners twice as much to send individual volunteers overseas for a year as it had paid Palms Australia (under a now defunct pilot scheme); concerns female volunteers in countries including East Timor had been subject to sexual harassment; that some volunteers felt they had not been adequately supported in terms of personal security during their time overseas and a claim one volunteer had been asked to prepare fraudulent funding applications by their superior while on assignment.

The quality of the volunteer experience has been the subject of an intense online debate following the publication of a blog by former East Timor Australian Volunteers for International Development participant Ashlee Betteridge this year.

Ms Betteridge, now a research officer at the development policy centre, Crawford school of public policy, ANU, said her 2012 placement had failed when a local team member refused to work with her because she was female.

''Despite notification of the problems to Austraining's in-country office, I received no intervention or advice on how to improve the situation,'' she said.

''During the period of time I was volunteering, Austraining were searching for a new country manager for Timor-Leste [and] we had a rotation of temporary managers which likely contributed to my concerns not being addressed.''

Fairfax also asked AusAID to comment on claims volunteers did not always have the experience for the roles they were called upon to carry out, that some found they were given only menial work and that volunteer allowances, which can be up to $46,100 per annum in Port Moresby, were not appropriate.

''AusAID contracts three organisations, the Australian Red Cross, Australian Volunteers International and Austraining International, to manage and deliver the volunteer program,'' the spokesperson said.

''Those organisations are responsible for managing volunteers … questions on these issues should be directed to those organisations.''

Fairfax requests for interviews with responsible staff from the Australian Volunteers for International Development providers were met with a joint statement, drafted in consultation with AusAID, detailing the cost areas associated with sending volunteers abroad.

Fairfax believes these criteria were also applied to the now defunct Palms Australia Pilot Volunteer Program.

The statement confirmed the average cost of a 12-month Australian Volunteers for International Development placement was $69,028, almost double Palms Australia's $35,000 per placement cost.

Mr O'Halloran said it made no sense for AusAID to reject responsibility for the delivery of the program. ''They indicate(d) to us all the time [during the pilot program] that they are answerable [for the quality of the programs],'' he said.