The public spending watchdog has stepped up an investigation into the sale of publicly-owned land worth more than £20m.
Sixteen parcels of land dotted around Wales were bought by a company based in Guernsey.
The auditor general for Wales, Huw Vaughan Thomas, said an initial probe raised a number of questions that warrant further in-depth investigation.
The Welsh government declined to comment.
The land was bought for about £21m by South Wales Land Developments Ltd in March.
It was bought from a public organisation which operates at arms length from the Welsh government called the Regeneration Investment Fund for Wales (RIFW).
Land near Cardiff was sold weeks before a council report on potential housing sites which could boost its value.