Manipulation at trading close

Has anyone else noticed the very large sell orders placed at close a pip or two up from the closing auction price for the last few days. Today it was a single sell order of more that 8.5m shares place either just before or at 4pm at 8.1c. I went to copy the market depth for this post but the order was withdrawn by 4.15pm. Yesterday there were two sells, one for about 10m and one for about 6m. Last Friday the same thing happened. I hadn’t noticed anything prior to Friday but I wasn’t looking.
I don’t know if it is to try and influence the auction close down by showing up as a huge sell for the purpose of
lower price accumulation. The huge sell bids are only there for the auction and a few minutes after following which they are withdrawn. I’ll report to ASIC for what that is with but am interested in anyone’s insight