Australia’s US ambassador, Joe Hockey has been dragged into the row involving travel services company Helloworld, in which he owns shares.

Mr Hockey, a good friend of Liberal Party treasurer Andrew Burnes who manages the company, asked staff to meet a representative of the company in 2017, The Sydney Morning Herald and The Age report.

Finance Minister Mathias Cormann on Tuesday had to defend a family holiday booked through the company in January 2018.

The senator paid $2780 for the flights to Singapore after it was revealed on Tuesday he got the holiday for free.

“The travel booked through Helloworld back in July 2017 was on commercial terms and should have been charged to my credit card straight away as instructed by me at the time,” Senator Cormann said in a statement on Tuesday.

“That is what I genuinely thought had happened.”

Senator Cormann and Mr Burnes are personal friends as well as colleagues.

Helloworld was chosen for a $21 million government tender just weeks before the trip was booked, but Senator Cormann said he had no involvement with the choice of the company or any influence over the process.