A sheriff's deputy in Texas has been accused of extorting Mexican motorists, threatening them with detention if they did not pay him immediately.

Henry James Jr., 45, was arrested Tuesday and pleaded not guilty in federal court on Wednesday.

A motorist complained to the sheriff's office that James required him to pay a fine immediately or be detained, the San Antonio Express-News reported in its Thursday editions.

Sheriff Victor Villarreal said in a statement that the department used its GPS technology to document several cases in which James stopped vehicles but did not call dispatchers. Four motorists complained of being stopped by James within one month.

Two undercover FBI agents posing as Mexican motorists were stopped by James for disregarding a stop sign, according to the criminal complaint.

The agents recorded James telling them that because they were Mexican, they had to pay him $150 or be detained until a judge could see them.