Some concert-goers had to wait two hours or more at a fruit fly checking station near the South Australian border on their return from triple j’s One Night Stand concert in north-western Victoria.

Biosecurity SA was unaware of the concert at Mildura on Saturday night and had six staff rostered to check passing vehicles for fruit and vegetables at the inspection station at Yamba.

Cars banked up for about six kilometres at the checkpoint.

Compliance officer Mark Langman says it was hard to get more staff at short notice.

“We were caught out there, but once the numbers were building up we called in extra staff to try and alleviate the problem,” he said.

“We have a reasonably large number of casual staff that we can call on but unfortunately, because it was such short notice, we could only get one extra in.

“We were able to open up one extra lane but we were just caught short with staffing.”

About 17,000 people were at the triple j event.