ASX figures are non-aggregated, whereas ASIC provides aggregated figures with a 4 day lag.
http://asic.gov.au/regulatory-resources/markets/short-selling/short-position-reports-table/
Shortman provides both with a graph showing levels are highest atm over the past year since refinancing news. So suggests to me that sp is being suppressed rather than thinking it is going to continue to fall, particularly when substantial holders continuing to buy.
http://www.shortman.com.au/stock?q=Tgs