Legal Definitions - ex rel.

The abbreviation ex rel. stands for the Latin phrase ex relatione, which means "on the relation of" or "on behalf of." In legal contexts, this phrase indicates that a lawsuit is being brought by one party (the nominal plaintiff) based on information or a complaint provided by another party, known as the relator. The relator is the individual or entity whose information forms the basis of the suit, even though the official plaintiff might be a government agency or another entity.

This procedural device is commonly used when a government entity has a public interest in a matter but relies on a private individual to bring the specific facts to light and initiate the legal action. The relator often has unique knowledge or evidence that is crucial to the case.

• Example 1: Environmental Protection Lawsuit

  Imagine a state's Environmental Protection Agency (EPA) files a lawsuit against a chemical factory for illegally dumping waste into a local river. The EPA was alerted to these violations and provided with detailed internal documents and eyewitness accounts by a former senior engineer who used to work at the factory. The case might be captioned as State Environmental Protection Agency ex rel. David Chen v. Riverbend Chemical Corp.

  In this scenario, the State Environmental Protection Agency is the official plaintiff, pursuing the case in the public interest. However, David Chen is the relator; he is the individual whose specific information and evidence prompted the lawsuit and on whose "relation" the agency is acting. He is the source of the crucial facts.

• Example 2: False Claims Act (Qui Tam) Action

  Consider a situation where a former employee of a company that supplies medical equipment to government hospitals discovers that the company has been consistently overcharging the government for supplies and billing for services never rendered. This employee decides to file a lawsuit under the False Claims Act, which allows private citizens to sue on behalf of the U.S. government to recover fraudulently obtained funds. The case might be titled United States ex rel. Sarah Miller v. MedSupply Solutions Inc.

  Here, the United States is the ultimate beneficiary and nominal plaintiff, as the fraud was committed against the government. However, Sarah Miller is the relator. She is the private citizen who initiated the action based on her unique knowledge of the fraud, acting "on behalf of" the government. If the lawsuit is successful, she would typically receive a percentage of the recovered funds as an incentive for exposing the fraud.