Tiger Woods has denied he has ever used human growth hormone or performance-enhancing drugs and promised to give his "full co-operation" to the federal authorities investigating controversial doctor Anthony Galea.
Galea gave the world number one 'blood-spinning' treatment first in his recovery from knee surgery and then when he tore his Achilles tendon 16 months ago.
That was an injury kept from general knowledge until yesterday, when Woods addressed a press conference in Augusta ahead of the US Masters.
"I kept re-tearing it," he revealed. "I used tape to play most of the year and I also went to hyperbaric chambers after the injections.
"It does help you heal faster. I did everything I possibly could to heal faster so I could get back on the golf course."
He added: "He (Galea) did come to my house. He never gave me HGH. I had PRP (platelet rich plasma) treatment."
Woods explained: "I've never taken any illegal drug, ever, for that matter."
Asked if federal agents had contacted him in relation to Galea's case, Woods replied: "They contacted my agent and will get full co-operation whenever they need me, but right now they haven't asked for my time."
The world number one has not played since mid-November and was in hiding for much of that time following the shocking revelations about his multiple affairs.
But the moment he announced three weeks ago that he was making his comeback at Augusta he was installed as favourite for the tournament.
"Nothing's changed. Going to go out there and try to win this thing," said Woods after facing the fans and meeting the press and emerging from both with a big smile on his face.
He is also still trying to put his family life back together - wife Elin will not be in attendance at Augusta - and has pledged to change his ways on the course as well as off it.
Criticised by the likes of golfing greats Tom Watson and Peter Thomson for his club-throwing and swearing, Woods has acknowledged the need to address that.
He interacted with fans far more than usual in practice yesterday and then said: "I'm actually going to try and obviously not get as hot when I play.
"But, then again, when I'm not as hot I'm not going to be as exuberant either.
"I can't be one without the other and so I made a conscious decision to try and tone down my negative outburst and consequently I'm sure my positive outburst will be calmed down as well."
Woods cannot wait for Thursday's first round. It will be his first competitive round for 144 days.
"It feels fun again. That's something that's been missing," he said.
"Have I been winning? Have I been competing? Have I been doing well? Yeah, I have - I've won numerous times the last few years.
"But I wasn't having anywhere near the amount of fun. Why? Because look at what I was engaged in.
"When you live a life where you're lying all the time life is not fun. And that's where I was.
"Now that's been stripped all away (by therapy) and here I am."Reuse content