Nicole Kidman and Keith Urban involved in altercation at the Sydney Opera House

Nicole Kidman and Keith Urban were reportedly involved in an argument at the Sydney Opera House. Photo / Instagram

Police were reportedly called to the Sydney Opera House last month after a man "swatted" actress Nicole Kidman with a programme during a performance she was at with her mum and husband Keith Urban.

According to the Sydney Morning Herald's Private Sydney section, witnesses allege a man in the audience of The Merry Widow grew agitated when Urban jumped to his feet to give the performance a standing ovation.

When Kidman joined her husband — along with the rest of the audience — in cheering on the cast, the man behind them allegedly began a heated exchange with the pair.

According to onlookers, Urban told the man he was simply appreciating the cast's talent, but things took a turn when the disgruntled audience member angrily "swatted" Kidman with his programme, leading Urban to accuse him of assaulting his wife.

The couple's date night took a turn when an audience member had words about them giving a standing ovation at the Sydney Opera House. Photo / Instagram

The couple were then escorted out of a side door by Urban's security guards, with police also called to the venue, the Sydney Morning Herald reported.

Police media confirmed officers attended the Opera House that night following reports of an argument.

"Police have been told a 53-year-old man and a 67-year-old man were both attending the entertainment centre when an argument broke out. Officers spoke to both men and no further action was taken," NSW Police said in a statement.

Kidman and Urban reportedly did not press charges against the man.

The outing came after Kidman completed a mandatory period of self-isolation at her $6.5 million Southern Highlands estate after a short trip to Ireland to film The Northman, alongside Alexander Skarsgard and Ethan Hawke.

According to the Daily Telegraph, the Oscar-winning star was given permission to self-isolate at home instead of a state-approved hotel for 14 days, despite what the majority of international arrivals are required to do under coronavirus travel restrictions.