Those charges are expected Tuesday morning and will be formally announced by the Mounties.
The RCMP are expected to lay fraud charges.
Both Harb and Brazeau were alleged in court documents to have defrauded taxpayers by claiming travel and living expenses to which they were not entitled.
Brazeau was suspended from the Senate in October along with onetime fellow Conservative Senators Mike Duffy and Pamela Wallin. The three former Conservatives were suspended without pay following an outside audit of their expenses.
Harb, who was a Liberal senator until his spending came under scrutiny through an external audit, retired in August after paying back $231,000.