A wad of cash shoved into a Houston police officer's sock led to his arrest after an undercover investigation that he had been taking money from drivers pulled over for traffic violations, officials said.

Matthias Dornellien, 24, was charged Saturday with theft by a public servant. He was later released after posting $5,000 bond.

The investigation that led to his arrest was conducted by Houston police and the District Attorney's Office.

"There were several complaints to HPD internal affairs division about an officer that was stealing money from people detained on traffic," said Donna Hawkins, a spokeswoman for the District Attorney's Office.

Marked money

An undercover investigator drove through the officer's patrol area Friday while carrying $273 in marked bills.

Dornellien stopped the car for a traffic violation. He pocketed the marked bills, handed the investigator a ticket then left without returning the cash, officials said.

Internal affairs investigators quickly stopped the patrol car and found the marked money — $173 on Dornellien's clip board and $100 in his sock, Hawkins said.

Dornellien was taken into custody at the scene. If convicted of the third-degree felony, he could face 2 to 10 years in prison and a fine up to $10,000.

Investigators haven't determined what impact the arrest might have on any other criminal cases Dornellien was involved with as a police officer.

Suspended with pay

Dornellien joined the department in November and was assigned to the south central patrol division, HPD officials said.

He has been relieved of duty with pay pending the outcome of the investigation.

Dornellien could not be reached for comment Monday. His arrest record does not list a lawyer for him.

Dornellien is a member of the Houston Police Officers' Union. The organization will not represent him in his criminal case, officials said.

Brian Rogers contributed to this report.

mike.glenn@chron.com