DENVER – A former surgery technician pleaded not guilty Friday to federal charges of stealing painkillers intended for patients at a Colorado hospital.

Prosecutors say Rocky Allen, 28, took syringes filled with painkillers at Swedish Medical Center in the Denver suburb of Englewood and replaced them with some other substance. That substance hasn’t been disclosed.

Allen is charged with tampering with a consumer product and obtaining a controlled substance by deceit.

Swedish asked about 2,900 people who had surgery between Aug. 17 and Jan. 22 to be tested for hepatitis B and C and for HIV.

A hospital spokeswoman didn’t immediately respond to a call seeking information on how many people had been tested and what the results were.

Denver attorney James Avery said two of his clients who had procedures at Swedish tested positive for hepatitis B.

“They’re more than anxious,” he said Friday. “They’re breaking down over it. They’ve never been diagnosed with hepatitis before, obviously.”

At least one other hospital where Allen worked, John C. Lincoln Medical Center in Phoenix, also offered testing to people who were patients when Allen was there, from late July to late September 2014.

The hospital said it began contacting patients after it learned about the Colorado case. The likelihood that a patient was exposed was “extremely low,” hospital officials said.

A Lincoln Medical Center spokeswoman didn’t immediately respond to questions Friday about how many people have been tested and whether any tested positive.

On Friday, a federal judge set bail at $25,000 and ordered Allen to get drug treatment.