Cameron, 20, has been at the New York Stadium since mid-November and scored one goal in 18 games, but is now back at Aston Villa after his deal ended.
And striker Slew, who has made seven appearances in the last month, returns to Blackburn without having scored.
Boss Steve Evans has also confirmed that a deal is in place in principle to bring in two new signings, one a striker, from an npower Championship club on Monday.
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