RIO DE JANEIRO – The spotlight intensified on the Russian doping issue at the Rio Olympics when American swimmer Lilly King taunted Russian Yulia Efimova.

Efimova, who was suspended from international swimming in 2013 after having tested positive for a banned substance, recanted here Monday night after settling for the silver medal behind King in the 100-meter breaststroke. She “made a mistake” in her use of the steroid 7-keto-DHEA, which she had claimed was a hidden ingredient in a supplement.

With Russian state involvement in a comprehensive program of doping, according to the McLaren report commissioned by the World Anti-Doping Agency, Russian golfer Maria Verchenova has come under increased scrutiny. She is the only Russian golfer qualified for the games.

According to Antony Scanlon, executive director of the International Golf Federation, Verchenova, 30, underwent blood and urine tests before the IGF declared Aug. 4 that she was eligible to compete in the Aug. 17-20 women’s tournament.

“We ensure it’s an even playing field with all the athletes,” Scanlon said.

Verchenova was unavailable for comment.

At the recent British Open, Rory McIlroy suggested the need for enhanced drug testing in golf, referencing how other Olympic sports police their athletes. McIlroy, a Northern Irishman who would have played for Ireland, said his blood was not tested before he announced June 22 that he would not compete in Rio.

“I on average probably get tested four to five times a year, which is very little compared to the rest of the Olympic sports,” McIlroy said. “Obviously I’ve gotten to know a lot of athletes over the years, and whether it be coming to their houses and doing blood and urine, I think drug testing in golf is still quite far behind some of the other sports.”

Under the IGF’s Anti-Doping Program, the registered testing pool began May 6 for athletes who were qualified for the Olympic Games. Additional athletes were added to the testing pool as they qualified. All athletes in the RTP have been subject to testing under the WADA code. That includes providing their whereabouts at all times, plus testing of blood and/or urine.

The PGA Tour does not conduct testing for the IGF anti-doping program, which is overseen by the IGF and the respective national anti-doping organizations. Yet, according to the IGF at the British Open, the organization had blood-tested fewer than 20 golfers as of mid-July. With 60 male and 60 female players ultimately qualifying for the Rio Games, that pool should have numbered closer to 140 or so.

“But, again, I don’t really know of any drug that can give you an advantage all the way across the board,” McIlroy said. “There are obviously drugs that can make you stronger. There are drugs that can help your concentration. But whether there’s something out there where it can make you an overall better player, I’m not sure. Physically, obviously, you can get stronger, recover faster. For example, HGH … you can’t really pick it up in a urine test.”

Bubba Watson, one of the four U.S. Olympic male golfers, underwent blood testing and understands the reasons for the enhanced test with golf’s return to the games after a 112-year absence.

“It’s definitely something you can live with,” Watson said of blood testing. “But now if they started the week after (the Olympics) and they do it for four years leading up to the Olympics, then, yes, that will be a problem. But for us it’s only happened for the last three months, but now if it was four years? I’m out.”

For Watson, the need exists in the run-up to the Olympics, but McIlroy sees the need as constant.

“I could use HGH and get away with it,” McIlroy said July 12. “So I think blood testing is something that needs to happen in golf, just to make sure that it is a clean sport going forward. But, yeah, I think if golf is in the Olympics and golf wants to be seen as a mainstream sport as such, it has to get in line with the other sports that test more rigorously.”