Collocations for fraud - noun

massive
serious (esp. BrE)
complex, sophisticated (both esp. BrE)
attempted (esp. BrE)
alleged
computer, mail (AmE), wire (AmE)
A bank lost several million pounds through a sophisticated computer fraud.

election, electoral, vote, voter
corporate, credit-card, financial, insurance, securities, tax, etc.

squad (BrE)
detectives from the fraud squad

case, charge