secret police

详细解释:秘密警察
【法】 秘密警察

英语解释：

名词 secret police:

a police force that operates in secrecy (usually against persons suspected of treason or sedition)

例句：

All the time he was in the city the secret police dogged his steps.他在该市逗留期间一直受到秘密警察的跟踪。