Rieu is considered the world's best-known modern violinist having sold more than 40 million records.
Rieu, also known as the modern "King of Waltz," was originally slapped with a 236,000 euro fine, later reduced, after a group of young Romanian pan flute players were on stage until midnight during a series of seven concerts in 2015.
Dutch law states that minors may not perform after 11:00 pm.
"The children were on stage at that time for a few minutes, but they were merely waving at the crowd at the end of the concert," his lawyer Sander Lely said after appearing at Limburg Regional court.
Although the group performed earlier "it is Andre Rieu's standard practice to have everybody on stage at the end of the evening to wave to the crowds," Lely told AFP.
"We think the fine is absurdly high and out of proportion."
With his curly locks and bubbly rock star personality, Rieu is considered the world's best-known modern violinist having sold more than 40 million records.
He is particularly famous for his waltzes, opulent stage sets and costumes and has invited celebrities including Sir Anthony Hopkins and David Hasselhoff to join him at his concerts.
In July 2015, in his hometown of Maastricht, Rieu had invited the children, together with Romanian pan flute virtuoso Gheorghe Zamfir, to play.
"Our investigations show that the pan flute ensemble of 11 Romanian children aged between nine to 12 years... performed unauthorised child labour between 19:00 pm until midnight," said Paul van der Burg from government-run Dutch labour watchdog, Inspectie SZW.
"There was no request for an exemption," to allow the children to play, he told AFP.
Limburg Regional court will hand down a judgement in the matter on December 4, Rieu's lawyer Lely said.
"He (Rieu) was not aware that he was the children’s employer as the children performed with Mr Zamfir," Lely said.
Rieu himself called the fine "absurd," according to Dutch entertainment website Show.