RUBEN Groenewald has insisted that he is not a cheat and blames a failed drugs test on asthma medication.

The burly 32-year-old fighter was tested after he was stopped by Thabiso Mchunu for the South African cruiserweight title in Bloemfontein in January.

"Yes, I failed the drug test when it was found I used a banned substance. That was part of the medicine I took because I'm asthmatic - it's not that I was cheating," said Groenewald in an emotional interview with Sowetan this week.

He said the substance found in his urine was Beta 2.

"It was from my inhaler. I use Combivent for asthma and not to enhance my performance," he explained.

Combivent contains albuterol and ipratropium, which are bronchodilators that relax muscles in the airways and increase airflow to the lungs.

"I was diagnosed in 1999 before I left for the United Kingdom in 2000."

Groenewald had already fought 11 times. He made his professional debut on March 27 1996.

"I felt like dying when I read that I had failed a dope test. I could not go anywhere because the news really disturbed me. The thought of quitting crossed my mind but I realised that leaving on such a negative note would kill me completely," he said.

Groenewald said he was tested by the Olympic Institute in England, which allowed him to box. He was the African Boxing Union (ABU) champion before he left for the UK in 2000. There he won the British Masters and the World Boxing Union straps in 2002.

Groenewald came home last year and passed all the tests before Boxing SA granted him a professional boxer's licence. He won three of his four fights before challenging Mchunu.

Boxing SA's acting chief executive Loyiso Mtya said they had forwarded Groenewald's medical certificate to the South African Institute for Drug-Free Sport, "who will conduct the hearing and make a decision about this matter".