A throwaway line reportedly made by Keith Urban to a fan may offer a fresh insight into his breakup with Nicole Kidman.

Kidman filed for divorce from Urban on September 30, but one of the musician’s biggest fans claims the singer hinted at the impending end of the marriage weeks before.

According to fan Dale Whiteside, who closely resembles the Queensland-born performer, Urban hinted at the split during a September 15 show in Saskatoon, Canada, during his High And Alive World Tour.

Whiteside told entertainment website TMZ that he met Urban while he was in Saskatoon, and they discussed how much alike they looked.

Whiteside said he told Urban, 58, that a couple had previously mistaken him for the singer at a music festival. They realised their mistake when they noticed Whiteside wasn’t wearing a wedding ring.

He said he then told Urban that the two main ways they could be told apart were the wedding ring and Urban’s many tattoos.

After being photographed with Whiteside, Urban then reportedly joked: “Next time, it’ll probably be just the tattoos.”

Whiteside says Urban joked about the split weeks before it was public. Photo: Instagram/TMZ

Whiteside was quoted as saying he had no idea what Urban meant until news of his split with Kidman came two weeks later.

Urban and Kidman, 58, had reportedly been living apart since June after he moved out of their Nashville home.

This was despite Kidman sharing a photo of herself that month cuddled up to Urban on Instagram to celebrate their wedding anniversary.

Eyebrows were also raised in July when an online interview with an Adelaide radio show ended abruptly after Urban was asked how he felt about his wife’s intimate scenes with other men in her movies.

It’s unclear whether Urban or his team ended the call or if the line dropped out because of a technical issue.

The couple have two daughters together – Sunday Rose, 17, and Faith Margaret, 14 – with Kidman seeking to be the “primary residential parent”.

Kidman filed papers with a Nashville court to dissolve the marriage on September 30 US time. The documents state she and country rocker Urban had “marital difficulties and irreconcilable differences”.

The filings include a marriage dissolution and childcare plan agreed to by the couple and submitted for court approval.

Kidman and Urban, two of the biggest stars to come out of Australia in recent decades, were red carpet fixtures throughout their two-decade relationship, with Urban joining his wife at the Oscars and Kidman attending music events like the Academy of Country Music Awards.