Jurgen Klopp spoke out against Marcelo Bielsa after the Leeds United boss confessed to spying on every team the Championship leaders have faced this season.
Bielsa held an extraordinary briefing on Friday where the Argentine coach revealed the extent of his analysis of opponents after being caught sending a staff member to spy on Derby County.
Liverpool use curtains to shield their Melwood training centre from the public and Klopp believes Bielsa, the subject of Football Association and English Football League investigations, is wrong to spy on training in the immediate build-up to matches.
"What do you think is the reason for the curtains?" Klopp asked reporters. "It's not there for all the sessions in the week because for most of the sessions it's not a big problem if someone had looked.
"But the last two, matchday -2 and -1, we use the curtains because it's not for anybody else. You understand a lot of things and train the set pieces then with the players in their formation. Everyone wants this information but normally nobody gets them, then you get the line-up when you come in the stadium.
"This has been clear for me, it's the same for everybody and really you have no idea who is going to play. You can see a line-up and still not know the system, but you could see that if you were there for MD -2.
"I can understand he wants to have all the information, we all want it, but we have to accept we don't get it. That's my opinion actually, you don't want someone around in these special sessions. Whatever you have prepared over the years has nothing to do with these last two sessions.
"It [Bielsa's briefing] was impressive and there's no doubt he is an outstanding coach and an outstanding role model with inventive styles, he's pretty busy on top but we are all busy. When I came in I didn't see 51 games of Derby, maybe I didn't have time but that's the truth.
"He's very well prepared and I respect him a lot but it's not like it should be. These two sessions and the last one before the game, only a couple of people should see them. I think we all agree on that."
| Marcelo demonstrates the analysis his team goes through for each opponent, and how it totals more than 300 hours of work pic.twitter.com/asfGA6Wadm— Leeds United (@LUFC) January 16, 2019
Klopp's close friend David Wagner left Huddersfield Town this week and the Liverpool boss hailed his compatriot's achievements at the Terriers, who the German led to Premier League promotion and survival ahead of this season's struggles.
"He's OK, not my job to tell exactly but he's OK," Klopp added. "I told him, I can tell you, he should be really proud of what he achieved, it was one of the most special stories in football in recent years.
"As a manager what he did was unbelievable to keep them so confident in a run with bad results, unlucky moments. It was so difficult there but we won it without performing and I felt bad.
"It's a part of life but in a few years people will think of Huddersfield thinking positively of him in this moment. Huddersfield thought they have a chance with a change to make something happen and hopefully it will work out, that's what he wants as well."