Anti-corruption officials in Nigeria have been forced to act after conmen impersonated their own investigators to pull off scams.
Corruption is enemy number one in Nigeria
The Economic and Financial Crimes Commission said fraudsters duped people out of large sums by impersonating its staff - including chairman Nuhu Ribadu.
The impostors allegedly persuaded people to pay bribes so as to quash investigations into non-existent cases.
Nigeria is cracking down on corruption in both the public and private sectors.
Last month, it revoked the licences of a dozen banks which it said were inefficient or tainted by corruption.
Since it was set up in 2003, the Commission has frequently exposed corruption in high places.
Its investigations have lead to the downfall of Nigeria's policy chief and a state governor.
Now, the agency has been forced to turn its attention closer to home.
It said the alleged fraudsters had "turned the name of the Commission into a goldmine by using it to dupe members of the public".
An undisclosed number of people are now standing trial for the alleged offences.