An acting deputy chief constable and two other officers have been suspended over allegations of gross misconduct and fraud.
Gordon Fraser took up the senior post in Leicestershire in January. He had worked in the West Midlands police force for 22 years.
Two unidentified West Midlands officers have been suspended and a member of the public is also being investigated.
The suspensions are all said to relate to officers' business interests.
In a statement Leicestershire Police Authority confirmed Mr Fraser's suspension from duty.
"This follows on from an allegation received in relation to a business interest connected to Mr Fraser.
"This is now an ongoing investigation and therefore further details cannot be given at this time," it said.
The matter was referred to the Independent Police Complaints Commission (IPCC) which recommended investigation by another police force.
Merseyside Police said it was conducting the inquiry.
"Merseyside Police can confirm that Chief Constable Jon Murphy is conducting an investigation into a Leicestershire Constabulary officer, two officers from West Midlands Police and a member of the public following allegations of gross misconduct and fraud.
"The investigation is currently ongoing so it would be inappropriate to comment further at this time."