Metro Transit Police said Wednesday that they’ve arrested two current and two former transit agency employees on allegations that they logged time they did not work.

The four have been charged with theft and conspiracy to commit theft, said Metro Transit Deputy Police Chief Erhart Olson.

Those arrested were former workers Alfred Atanga, 50, of Bowie and Lakisha Gardin, 34, of Forestville and current employees Empriss Jacobs, 28, of Fort Washington and Keesha Richardson, 32, of Upper Marlboro. They were charged with theft valued at an estimated $25,000.

Atanga was arrested Tuesday evening by the Prince George’s County sheriff’s office. Jacobs and Richardson were arrested Wednesday at the customer service office at the agency’s customer service call center near the Prince George’s Plaza station. Gardin turned herself in to Metro Transit Police.

Officials said the investigation began late last year after Metro’s Office of Inspector General received an anonymous tip. Investigators soon found records indicating that the alleged theft had been going on for several months.

Metro Transit Police joined the agency’s Office of Inspector General in the investigation and submitted evidence of wrongdoing to the Prince George’s state’s attorney’s office. The case was presented to a grand jury, which last week returned indictments, Metro officials said.

The complaint alleges that Atanga, a former supervisor, provided employees with “pay for hours not worked” at the customer service office, Olson said. The employees were information specialists, Metro officials said.

After being arrested, the two current employees were placed on paid administrative leave, pending the outcome of an administrative investigation. Jacobs has been with the transit agency since June 2004 and Richardson since April 2002. Gardin worked for Metro from December 2004 until July, and Atanga worked there from January 2008 until last September, officials said.

Olson said that the investigation is ongoing but that he does not think any other people are involved. “The job of the Transit Police and the inspector general is to ensure the authority is not getting defrauded by anybody, including its employees,” Olson said.

Staff researcher Jennifer Jenkins and staff writer Ruben Castaneda contributed to this report.