She's been routinely late at every show during her Australasian tour, with delays of more than two hours angering fans waiting to see Madonna.

She also dressed as a clown and acted drunk during a Sydney sideshow that shocked even her diehards.

But what happened during Madonna's Brisbane show last night might just take the cake.

The UK pop singer had invited a group of fans up on stage, when she pulled down a girl's strapless top, exposing a breast.


"She's the kind of girl that you just want to slap on the a** ... and pull," said Madonna, eyeing the girl up before yanking her top down.

"Oh sorry, sexual harassment," Madonna said afterwards, giving the fan a hug. "You can do the same to me if you'd like."

Fans were reportedly offered refunds to Madonna's second Brisbane show after the first was delayed by 2.5 hours.

The delays, which also occurred at Madonna's two New Zealand shows, are believed to have cost her tens of thousands of dollars.

The delayed start meant a massive explosion in the wages bill for the venue operator and it's estimated almost 100 patrons received refunds on the night.

A music industry insider says the wages bill for police, security, ushers, event staff, car park attendants, caterers and even taxi rank supervisors will have blown out enormously.

All additional expenses are passed on to the promoter, however who foots the bill depends on the deal struck up between Live Nation and Madonna's management.

The insider told AAP that it would easily cost "tens of thousands" of dollars when you also factor in refunds.

"Any delays like that are additional costs but they are not borne by the venue. They're all costs picked up by the promoter or the band management," the insider said.

"The fact they agreed to refunds before she came on stage...they're approved by the promoter and you'd think there would have to be more today.

"It's hard to think the promoter would pay for it, it would be covered by the artist's management and it would easy be tens of thousands of dollars."

Live Nation refused to comment on who picked up the tab for the additional costs incurred by Madonna's late start.

The Brisbane Entertainment Centre is serviced by a rail line but the last train departs at about 12.15am.

Anyone who travelled by train to Madonna's concert would have had to have caught a taxi home or called to be picked up.

One reason put forward for Live Nation handing out refunds is that it was cheaper for them to return money than organises buses, at the eleventh hour, to ferry patrons to the city.

"The real cost would be paying for additional public transport at short notice. That's where they would rack up bills. It would be easy to go down the path of returning money than rack up those costs," they said.

- With AAP