The Winnipeg Blue Bombers announced Monday that running back Andrew Harris has been suspended for two games after he tested positive for a banned substance.

In a statement, Harris said he has been tested for drugs three times this year: on March 1, July 2 and July 12.

“Somehow on July 12, just ten days after a test that came back completely clean, I was notified that I had tested positive for the first time in my career with very small trace of a banned substance,” he said.

“I’m still in shock and disbelief at the news. I immediately thought there had to be some kind of mistake.”

Harris goes on to say the timing shows he was not using a banned substance to enhance his performance and that he was unaware he was consuming any supplements that contained anything banned.

“Based on the fact pattern, this is clearly a case of product contamination,” he said.

Harris noted the substance in question usually stays in the body for up to four weeks “so trace amounts in my system 10 days after testing cleanly makes it clear that I did not purposefully ingest any banned substance.”

A University of Manitoba Assistant Professor of Exercise Physiology, Stephen Cornish said he urges anyone who takes supplements to check if they have a Natural Health Product number, an approved certification by Health Canada.

“Not everyone abides by the governing agency, in terms of getting a NHP number.” Cornish said.

“If you don’t have a NHP number, the chances of that being contaminated with something else are quite a bit higher.”

Cornish said it would be “slim-to-nil” to find a product with a NHP number. He believes some companies may cut corners.

“There are probably a few companies that may be a little more devious in nature, trying to get their product ahead of other products.”

The running back apologized to his team, saying he’s devastated about missing the two games. He wants young athletes and football fans to know that he would never cheat.

“I’ve worked very hard to get to where I am, and I pride myself on being not only a great role model to my daughter and youth throughout our country, but to my peers as well,” he said.

“As unsettling and painful as this is to me and my family, I hope this can be a helpful reminder to all athletes about being extremely cautious and aware of what they are taking and putting into their bodies.”

President and CEO of the Bombers Wade Miller said in a statement that the team supports the CFL’s policy on performance enhancing drugs and is cooperating with the league.

“The Winnipeg Football Club also supports Andrew Harris through this extremely difficult and unfortunate situation. We look forward to Andrew re-joining us on the field for game days following the bye week,” he said.

-With files from CTV's Jason Gaidola