Deputy Premier Susan Close has joined the Premier in admitting to not having seen the full business case for merging the universities of Adelaide and South Australia, amid questions about whether anyone in the Malinauskas Government read it before committing nearly $450m of taxpayer support.

The university councils only received the full business case for consideration last week, but approved it within days. Both universities say full details will be kept under wraps, due to commercial considerations, and they will only publicly release a summary.