Roscommon Co Council has confirmed that three of its officials are under investigation for breaking planning regulations.
In a statement, the council said that two have been suspended and the third has resigned.
The inquiry was prompted by claims that officials had broken council rules by helping in the preparation of planning applications.
One of the suspended men has admitted helping prepare an application in another county under an assumed name.
The council insisted that it has taken all necessary steps to protect the independence and integrity of its planning process.