maggots??
If the body had been wrapped in plastic and buried under concrete would there be maggots? There have to be flies to lay the maggots and, i'm not a forensic expert, but would the maggots still be alive? Don't even maggots need air to live? And I'm sure they were wriggling when we saw them.
Of course, i don't know how long the body had been buried there or where it had been kept earlier. Any CSIs reading this??