1: Cover-up file conceals, ultimately, wrongdoing by one female (3,4)
2: Deciphered code in a sea-nymph (7)
3: Employ heart-broken Spartans where disaster came to pass. (11)
4: Troubled tenor with a transposition (2,3,5)
5: Space left by dry loch (9)
6: Startled, grabs sailor (3)
7: University with unconventional stance about unconventional person (7)
8: Hell, he's got the upper hand in tennis (5)
13: Incomplete raw data lies in largely unexplored regions (4,7)
15: Carry out country's acts of philanthropy (9)
18: In Indonesia, returning from the western part a must (7)
20: In a dream I venerate clothing (7)
21: Road reaches objectives. (7)
22: Part of speech idealists rebuke (5)
23: Excessively sentimental dunderhead in the river (5)
26: Road without a pole (4)