Three employees of the Los Angeles County Assessor's Office claim County executives and lawyers have given improper property tax discounts, exemptions, and refunds to well-connected landowners, and said they faced retaliation at work after speaking up.

Stephen Adamus, Yvonne Austin, and Scott Woods said in a retaliation lawsuit filed last week that when they raised objections and concerns the three were transferred to menial jobs and effectively demoted. The plaintiffs were not able to discuss the legal complaint, their attorney said.

Several law enforcement sources told NBC4 criminal complaints alleging similar activity had been received by local and federal authorities but were unable to confirm whether or not formal investigations had been opened.

"Simply put: this lawsuit is groundless," Assessor's Office spokesman Steve Whitmore said in a statement. He said the County was unable to address the specifics of the employees' complaints because of the litigation.

"Suffice it to say these allegations are completely unfounded and we are certain that the claims will be found meritless once the facts of the case are presented," Whitmore said.

Adamus, Austin, and Woods said they were transferred from their jobs in March after complaining about a series of alleged improper property tax actions, including one involving the RAND Corporation's property in Santa Monica and a parcel swap in San Marino tied to a County Supervisor Kathryn Barger's brother.

Austin was a supervisor in the Legal Services Section, Woods was a Property Assessment Specialist, and Adamus worked at the department's headquarters. They allege that they were moved to menial positions.

The suit demands compensation for physical, mental, and emotional injuries, as well as the cost of treatment, lost wages, damages, and legal fees.

The complaint said RAND challenged a tax assessment after the Assessor's Office staff determined it did not meet the standard for a, "welfare exemption," which is a tax exemption extended to entities that provide a community benefit. RAND took the case to LA Superior Court but settled before trial.

"In the settlement agreement, RAND was granted exemption from paying any property taxes in perpetuity. RAND was also refunded the $1,500,000 it had paid even though the statute of limitations for requesting those funds had clearly expired," the lawsuit said.

RAND denied anything improper happened and said the allegation was wrong.

"The claims made in the Oct. 7 complaint against the County of Los Angeles regarding RAND's prior lawsuit against the County are inaccurate and have no basis in fact," it said in a statement. "As a 501(c) (3) nonprofit organization whose contracts and grants fund policy research that serves the public interest, RAND has been deemed entitled to the welfare exemption from property taxes."

Supervisor Barger denied her office had any role in the property tax decisions involving the San Marino land swap in which her brother was a trustee for the parcels involved. "Supervisor Barger's office had no involvement in this instance," said spokesman Tony Bell.

"I have full faith and confidence in our Assessor Jeffrey Prang and his office to discharge their duties ethically and have no reason to believe that anyone is given preferential treatment, including my brother," Barger said.

The plaintiffs suggested that Barger's elected position had influenced an allegedly unusual reclassification of the property transfer, re-listing it as an "eminent domain" transfer, thereby reducing or eliminating its property tax liability.

A County official familiar with the transaction said Barger's brother had no financial interest in the land swap and confirmed Barger's office had not made a request for special consideration.

The Assessor's Office faced criminal accusations of a similar nature in 2012 when the LA County District Attorney's Office charged former Assessor John Noguez with dozens of felonies for allegedly accepting bribes in exchange for reducing taxes on certain properties.

The DA's Office said Noguez took part in a "massive corruption scheme" to manipulate assessments. That case is moving toward trial with a progress hearing set for December, the DA's Office said Tuesday.