Sweden have confirmed a member of their coaching staff got into a closed South Korea training session and was asked to leave, leading to a squabble between the teams over spying ahead of their World Cup game on Monday.
A Swedish scout used a house near Korea's training base in Austria this month to watch training sessions using a high performance telescope and video camera.
"It took a long car journey up the mountains to reach the house, but it was a perfect spot to observe the Korean team's training," Lars Jacobsson, a member of the Swedish coaching staff, said on Sunday.
He had earlier been kicked out of a closed training session, after failing to convince the Koreans he was a passing tourist, and persuaded a local couple to let him use their house, overlooking the training facility, to watch their rivals working on their World Cup routines.
The incident has created a frosty atmosphere between the teams ahead of their game in Nizhny Novgorod.
Andersson says his team analyses all opponents and the incident has been overblown, but added "It's very important that we show respect for opponents ...
"If it has been perceived in another way, we apologise."
At a news conference South Korea coach Shin Tae-yong played down the incident and said he mixed up shirt numbers in an attempt to confuse the scout.
"We switched them around because we didn't want to show our opponents everything and to try and confuse them.
"They might know a few of our players but it is very difficult for Westerners to distinguish between Asians and that's why we did that," Shin said.
"All coaches probably feel their opponents are always spying on them. I think it's perfectly natural that we all try to get as much information on each other as we can."