A 25-year-old man from Bangor has been arrested in connection with a suspected tax fraud following raids in Northern Ireland and Scotland.
He was one of two men arrested in connection with the suspected VAT repayment fraud, thought to be worth more than £350,000.
A 39-year-old from Ayrshire, Scotland, was the second man arrested in the swoop.
Investigators from HM Revenue and Customs assisted officers from the PSNI in carrying out three property searches in Bangor, Co Down, and Ayrshire.
The pair were arrested on Wednesday during early morning raids.
David Odd from HMRC said the arrests sent out a clear message to those involved in tax fraud.
"We take tax fraud extremely seriously and will pursue anyone believed to be involved in this type of crime," he said.
HMRC's Ron Barrie said investigators had been made aware of a VAT fraud involving people from Northern Ireland and Scotland.
According to HMRC, tax avoidance and fraud costs the Exchequer around £15bn in lost earnings a year.