The couple, a Portuguese woman and a Spanish man, were arrested on a flight departing for Spain.
They had recently been in South Africa and were quarantining alongside people with the Omicron variant.
It is not known if the couple had tested positive for the Omicron variant of COVID.
Police in The Netherlands detained a couple who slipped out of their quarantine hotel after returning from South Africa, according to local reports.
The couple, who have been identified as a Spanish man and a Portuguese woman, boarded a flight to Spain at Amsterdam's Schiphol Airport on Sunday night but were stopped by Dutch national police, Dutch outlets Het Parool and Der Telegraaf reported.
"The arrests took place in a plane that was about to take off. Both persons have been transferred to the GGD," the national police wrote on Twitter. The GGD is the country's public health body.
The pair had fled from their quarantine hotel in Kennemerland, near Amsterdam, at 6 p.m. local time on Sunday, Der Telegraaf said.
They were among 61 people being held in the hotel after testing positive for COVID on their return from South Africa, Het Parool said.
As of Monday, 13 of those cases have been identified as the Omicron variant, the newspaper added.
It is not known which variant the couple tested positive for, or whether they were on the same flight back to Amsterdam as any of the 13 people who tested positive for the Omicron variant.
The couple were able to leave their quarantine hotel with ease, as occupancy is voluntary and not legally enforced in the Netherlands.
"There is security present in the hotel, but it is true that people stay there completely voluntarily," Marianne Schuurmans, the mayor of Haarlemmermeer, told Dutch TV network WNL.
"Security guards advised the couple not to leave, but there was no legal title to hold them yet.
"We really did not expect that people would flee."
However, Der Telegraaf said that the pair could still be prosecuted for violating quarantine.
The first cases of the Omicron variant were identified last week in several southern African nations. As of Monday, Omicron cases have now been reported by the UK, Canada, Israel, Belgium, the Netherlands, Australia, and Germany.
Scientists are racing to learn more about the new variant, which contains a large number of mutations.
The World Health Organization said on Sunday that it is "not yet clear whether Omicron is more transmissible" than other COVID variants such as Delta.
A number of countries have already enforced travel restrictions in an attempt to prevent the spread of the Omicron variant, though Dr. Anthony Fauci said Saturday that the variant "invariably is going to go all over."