The Saints boss was quizzed on the topic in the aftermath of Leeds United gaffer Marcelo Bielsa having admitted to sending one of his own to a closed training session ahead of his side's clash with Derby County on Friday.
The Argentine said he had a 'different viewpoint' when Rams boss Frank Lampard told him that he hasn't respected the rules of fair play, but the FA are investigating the incident regardless.
Southampton's next clash sees them face Derby in the FA Cup on Wednesday and boss Hasenhuttl was quizzed on his opinion of the matter, and whether he had ever sent people to spy on opponents in the past.
“Yeah, it's normal in Germany,” the Austrian said. “We could because it was open to the public.
“You send the guys there and you could see who was training, who wasn't, and if there was a new coach you could see what he was doing from the beginning.
“But it was open to the public so everyone could do it. I wasn't standing there myself, but I did send spies there. 'Spies' if you want, or just normal visitors.
“In Germany it's a little bit easier because they love public training sessions, so it's not a problem to spy on such training sessions.
“But there are still a few training sessions that are without the public and there it also happens that sometimes you have to pick someone out of the woods behind the pitch!
“But it's good I think that in England they're signalling that it's unsporting and unfair, and it won't happen in the future if the fine is high.
“People will see that it doesn't make any sense to take that risk.
“I also have had sessions that were spied on by other clubs and so I think that if they're sending a signal that it's unfair and unsporting then it's something I can agree with, absolutely.”
With a spot in the fourth round of the FA Cup at stake, Southampton host Derby at St. Mary's stadium on Wednesday, with kick-off taking place at 7:45pm UK time.