The Australian Institute of Superannuation Trustees (AIST) has asked Treasury to explain how it estimated the $467.1 million in implementation costs for SuperStream.

AIST chief executive Fiona Reynolds has written a formal letter to Treasury, requesting a briefing on the SuperStream levy to be held in the next couple of weeks.

Reynolds told InvestorDaily AIST would bring IT project specialists to the briefing to analyse the financial costing of the project.

"As part of this analysis, AIST wants to get a better appreciation of the extent to which the expenditure ties in with the wider implementation of standard business reporting, and the extent to which the expenditure provides direct benefits to employers," she said.

The request follows the Parliamentary Joint Committee public hearing on the super levy and the publication of the proposals by Treasury and the Australian Prudential Regulation Authority (APRA) on Monday.

"The Treasury/APRA paper only provides information on high-level deliverables and there have been no planned expenditure reports given to the SuperStream working group," Reynolds said.

"AIST members were surprised by the high level of the proposed levies and the lack of detailed information about the expenditure being funded by the levy."

She said she was particularly concerned about the lack of financial details given to the SuperStream working group, which was part of the Stronger Super consultation process, and that the first estimates of the project were announced during the presentation of the federal budget.

"While our participation in the SuperStream working group has given us an understanding of the functionality being developed to implement SuperStream, we do not have a detailed appreciation of the proposed associated expenditure," she said.

"On the face of it, the ATO (Australian Taxation Office) appears to be able to employ many hundreds of people to work on the project during 2012/13."

Treasury has estimated that it will require $90 million to fund the implementation of SuperStream in 2012/13.

It has also estimated that over the year 2011/12, already $31.4 million will be spent, which also needs to be recouped through the levy, bringing the total levy to be raised in 2012/13 to $121.5 million.

In total, the SuperStream levy will amount to $467.1 million spread over seven years.

This figure includes only the estimated cost of implementation by government agencies, while the additional cost for the industry is likely to add several hundred million dollars more.