She is still missing, and the police now suspect that she may have been a victim of foul play. [=that she may have been murdered or harmed in some way]她仍然下落不明，警方怀疑她可能已经惨遭杀害。

There is no evidence of foul play.没有证据证明是谋杀。

The company's deal with the government has brought cries/accusations of foul play [=claims that there have been unfair or dishonest acts] from its competitors.有指责称这家公司与政府之间的交易存在非法勾当。