Mo Farah's coach Alberto Salazar often warned his athletes not to touch his bags because he feared contaminating them with his testosterone gel, a former member of his camp has told the Guardian.

Albert Kupczak, a massage therapist at the Nike Oregon Project from 2008 and 2011, also said he went to the United States Doping Agency before the London 2012 Olympics because of his fears anti-doping rules were being bent or broken by Salazar.

Kupczak, who said he massaged every athlete at the Oregon Project on a regular basis, including Farah, Galen Rupp and Kara Goucher, said that Salazar would frequently bring Androgel, a banned anabolic steroid, on training camps. The World Anti-Doping Association rules forbid support personnel to carry such drugs without good reason.

Kupczak said: “When we were at an airport together Alberto would say: ‘Don’t let anyone touch my bag I have my testosterone cream in there – I don’t want anyone to get contaminated accidentally’. My thought was: if you are taking testosterone for yourself there are so many ways you can do it. You can do it in a tablet form. You can do it injection form. You can do it in an implant. So why risk something that could possibly contaminate the athlete? That is nuts. But then we would say, it’s his way. That’s Alberto.

“It was one of those things that was so common that we didn’t really take notice of it. We would just think he’s got his damned Androgel again.”

The Guardian received no response when it put Kupczak’s claim to Salazar via email. However it is known he is preparing a detailed rebuttal to a Panorama documentary that claimed he gave Rupp testosterone when the athlete was 16 and committed several other doping violations. Rupp and Salazar deny the allegations and there is no suggestion Farah has committed any wrongdoing.

In a statement to the Guardian earlier this month, Salazar said: “I have said all along that I believe in a clean sport, hard work and I deny all allegations of doping. Given the time and effort the BBC and ProPublica committed to making these false allegations I hope that media and fans will afford me a short time to show the accusers are knowingly making false statements.”

Kupczak, who worked at the Oregon Project for a few months in 2006, also told the Guardian of a culture “where inhalers were so prevalent, it didn’t even phase me if people had one”. Yet in Kupczak’s view that culture became increasing secretive after he returned in 2008 and had become worse by 2011, by which time Farah had joined the camp.

“When I first met Alberto in 2006 he was great,” he said. “He was fun. He was open. He would help anyone. He was a good man. He gets some wild ideas – he would want to fly to altitude to do a workout and it would happen, or he would order some laser for $20,000 that is worthless. He would do crazy things like that. As a therapist it was fun. I was like, what crazy stuff will we come up come up next?

“But when I went back in 2008 he had changed. And he continued changing by the week. Things got really secretive.”

Kupczak, the latest former employee of Nike’s Oregon Project to come forward with claims against Salazar – the tally stands at nearly 20 – also said he spoke to Usada three years ago. “I wanted to alert them before the Olympics because I thought they could watch more closely or do something about it. I probably contacted them in June 2012, and I spoke to them later in that month.”

Kupczak believes that, in the next few days, Salazar will try to discredit Kara Goucher, the 2007 10,000m world championship bronze medallist, and Steve Magness, an assistant at the Nike Oregon Project, who made some of the more serious accusations against him in the Panorama documentary. Kupczak said he can vouch for his former colleagues' testimony and character.

“I absolutely believe Kara,” he said. “I trust completely that she is honest. And Steve has complete integrity. He’s such a science guy that he wants to do it the proper way. Doping, in his mind, would take away from his science and his research.”

Kupczak expects that, when Salazar issues his reply to the BBC, there will confusion in the athletics world with people unsure who is telling the truth. He believes the best way to cut through the impasse would be for Usada – or another official body – to start interviewing every member of the Nike Oregon Project under oath.

“I would love to see that,” he said. “That is always when it comes out because you can’t lie because if you do you’ll have perjury charges. I would love to see all this come under oath, let’s do it. They always catch you. They always do.

"If it was anyone else but Alberto they would say: 'Enough is enough, we have heard this from enough people.' It's similar to the Lance Armstrong case, where they didn't have any positive tests but they had enough witnesses that they said you're done."

Kupczak said the bond between Salazar and Rupp was so close Salazar would sometimes take over the massage duties from him when they were at training camps. “Sometimes we’d be somewhere and Galen likes his massages in the evening, so I would start to work on him and Alberto would say: ‘Al, you take the night off, I’ll give Galen a massage.’

“At first I was a little taken aback. I was thinking am I doing a good job? But then I realised they have a peculiar arrangement, it’s beyond son and father, like some people say, so I’d just laugh it off and think I’ve got the night off, good.”

(Guardian service)