Porto boss Sergio Conceicao said Arsenal manager Mikel Arteta insulted his family in the loss to the Gunners in the Champions League last 16.
The Gunners went through to the quarter-finals after a 4-2 penalty-shootout victory thanks to two saves from David Raya.
“What Arteta said, towards the bench in Spanish, he insulted my family,” Conceicao said in the news conference.
Arsenal club sources have said that Arteta denies the accusations.
After the final whistle the two managers appeared to have an intense discussion on the pitch before being separated.
“He should focus on training his team,” said Conceicao. “The result was injust. The team deserved to go through.”
Before Conceicao’s comments, Arteta was asked about the confrontation at the end and said: “No comment. Thank you very much.”
The first leg in Portugal saw Porto win 1-0, but Leandro Trossard’s goal in the 41st minute at Emirates Stadium levelled the tie, sending it to extra tine and then penalties.
Raya’s two saves helped take Arsenal into the quarter-finals of the tournament for the first time in 14 years, with the last-eight draw taking place on Friday.
In 2020, Conceicao also accused Pep Guardiola of being “unpleasant” and using “ugly words” during a defeat to Manchester City in the Champions League.