McLaren's second report into Russia's doping activities found proof over 1,000 Russian athletes were involved in using banned substances.
McLaren's second report into Russia's doping activities found proof over 1,000 Russian athletes were involved in an "institutional conspiracy" to cheat using banned substances.
While Russian track and field athletes remain banned from international competition, McLaren believes there is "genuine will" within the country not to repeat the grave errors of the past.
"Since my last report (published in July), I've had the opportunity to meet several of the Russian officials and we've discussed that very point," he said.
"I've been impressed with their sincerity and their willingness to try and change. That's a tough job and not easy and there are a lot of people that have to be convinced -- coaches, trainers and others.
"I think there's a genuine will to change, but it'll be a hard job. It's not going to happen overnight. The culture's got to change."
Although McLaren found proof "senior officials" within Russia's ministry of sports actively supported the doping programme, he unearthed "no evidence" President Vladimir Putin knew about it.
Asked how Russia's doping programme could be "state-sponsored" if the president was unaware of it, McLaren said it was a question of vocabulary.
"If you've got a centralised system and an infrastructure and you draw on different parts from different organisations under the umbrella of the ministry of sport, you could describe that as state-sponsored," he said.
"I don't think the Russians think of it that way because they think of 'state-sponsored' as being the central government decision-makers, which would be Putin and his inner circle.
"They're not involved, so in their terms it's not 'state-sponsored'. But if you look at the facts, then we know the ministry of sport's involved.
"I think different people would put different labels on that. It's just a vocabulary game."
McLaren's two reports showed how the Russian secret service devised ways of prising open sealed sample bottles so tainted samples could be removed and replaced with clean ones.
McLaren's first report dubbed it 'Disappearing Positive Methodology' and he is confident such practices cannot be repeated.
"I can't speak for anywhere else, but in Russia I don't think it will happen again -- at least not the way we know it," he said.
"For one thing, the whole group that were doing the bottle cap removal has been disbanded. For another, the lab is no longer available to do Disappearing Positive Methodology.
"I haven't checked this point precisely, but I'm sure WADA (the World Anti-doping Agency) has taken steps to make sure there isn't continuing false reporting going on.
"So I think the schemes that I've describe are finished."
WADA is already looking into doping practices in Kenya and McLaren believes other countries should be investigated, although he says costs could prove prohibitive.
"There probably is scope to look at other countries, but these investigations are expensive, they're time-consuming," he said.
"You have to have a particular hypothesis that you want to look into. So it's not just a simple case of looking into another country.
"You really have to have some grounds and then you have to have some evidence. It's a hard process to get started and it's expensive and it takes a lot of time.
"Yes, there are other countries that probably need looking into, but whether that will happen or not, we'll have to see."