Guy Sebastian has told a court how thrilled he was to be the opening act for global pop superstar Taylor Swift during her Australian Red Tour.

But what was meant to be a career highlight soon became the centre of a messy legal battle with his former manager.

The Aussie Idol winner, 42, took the stand in the NSW District Court on Wednesday, recounting how ‘honoured’ he felt when ex-manager Titus Day informed him in 2013 that he’d secured the coveted support slot on Swift’s stadium shows Down Under.

‘I was alerted to the fact that I was to be supporting Taylor Swift, which obviously is a big deal – Taylor’s a huge artist, and it was a massive get to get that tour,’ Mr Sebastian said, according to Newswire.

‘I was really honoured.’

Guy Sebastian (pictured) has told a court how thrilled he was to be the opening act for global pop superstar Taylor Swift during her Australian Red Tour

The Aussie Idol winner, 42, took the stand in the NSW District Court on Wednesday, recounting how ‘honoured’ he felt when ex-manager Titus Day informed him in 2013 that he’d secured the coveted support slot on Swift’s stadium shows Down Under. Swift is pictured

The court heard that unlike his own tours – which Sebastian admitted ‘weren’t fruitful’ financially, due to him footing the bill – the Swift gigs were set to be lucrative, with a guaranteed payment locked in.

‘This was an opportunity where it was a guaranteed sum I was being paid,’ he explained.

Keen to put on a standout performance, Sebastian said he flew in a close friend to join him on stage and spent a significant amount assembling a high-calibre band.

‘I really made that band as slamming as I possibly could and wanted to do a really good job of this,’ he said.

While he was due to earn around $500,000 from the tour, Sebastian said approximately $180,000 went towards costs, including his hand-picked band.

However, things quickly turned sour when Sebastian discovered a chunk of that money was allegedly never paid to him.

The court heard a total of $494,000 was transferred by a booking agent into the account of Mr Day’s company, 6 Degrees Management.

The Crown alleges that after taking his $59,000 commission, Day should have passed on $435,000 to Sebastian.

Instead, it’s claimed the singer only received $247,500 – meaning a further $187,000 allegedly went missing.

The court heard that unlike his own tours – which Sebastian admitted ‘weren’t fruitful’ financially, due to him footing the bill – the Swift gigs were set to be lucrative, with a guaranteed payment locked in

Sebastian told the court he was initially led to believe the remainder of the funds would follow shortly after.

‘Within seven or 14 days, but it was clearly indicated to us when the $247,000 was transferred that there was going to be a reconciliation on weeks of the whole tour … we were told that the full reconciliation would be done really soon,’ he said.

He added that his bookkeepers repeatedly requested those figures so they could complete his tax return, but the full breakdown ‘was never received’.

Despite the missing money, Sebastian admitted he didn’t immediately push for answers.

‘In the years following, I assumed it was taken care of,’ he told the court.

Day’s barrister, Thomas Woods, last week conceded that his client did fail to pass on money to Sebastian on some occasions, but claimed the core legal issue is whether the conduct was criminal.

‘For many of the charges, the real question is not going to be whether my client failed to transfer the money to Sebastian but whether his failure to do that was criminal,’ Woods said.

Sebastian signed with Mr Day’s 6 Degrees management company in 2006 – three years after winning Australian Idol. The pair had previously worked together at 22 Management.

While the relationship began positively, Sebastian told the court that ongoing issues over statements and payments eventually led to him cutting ties with Day in 2017.

The singer launched Federal Court action against his ex-manager the following year.  Day later filed a counterclaim.