DENVER -- Postal inspectors and police are searching for a person who is sending out letters accusing a Monument landscape business of being associated with al-Qaeda and terrorism.

The Douglas County Sheriff's Department and Denver postal inspectors are asking for the public's help to find the hoax mailer who has sent about 50 letter to residents in the Douglas and northern El Paso County.

Police said the letters falsely accuse the owners of Concepts In Landscape, located in Monument, Colo., of being supporters of the Taliban and al-Qaeda. The letters also say that the owners are responsible for sending out the letters, which police said is also untrue.

“This is an extremely unusual but a serious violation of the use of the U.S. mail for unlawful purposes,” said Denver postal inspector Kathleen Roberts.

The hoax mailer will possibly face felony charges of harassment and criminal impersonation and could face up to three years in prison.

Anyone with information about the hoax mailer is asked to contact Denver postal inspectors at 303-313-5320.