1: I shall be sick! (3)

3: Scantily-clad in only a shred of fibre. (5)

5: Yellow fowl (7)

7: End is close, doctor surreptitiously revealed (9)

9: Say again 'Others had food' (7)

11: Allow meathead into mine opening (5)

12: Aliens set off (3)

1: Tavern drink for the auditor, one with access to confidential information (7)

2: Smoked salmon for the auditor with hair (5)

3: Very clever fish ain't at sea (9)

4: Sort of uninitiated cheat (3)

6: Heads appearing strange in distorting lens (7)

8: Reportedly viewed some of play (5)

10: In all, just a little peak. (3)