Prime Minister John Key has defended the high travel bill for one of his backbench MPs.
Paul Foster-Bell has also faced accusations of poor management after reportedly having 12 staff leave over a period of three years.
The former diplomat and list MP racked up a $61,090 travel and accommodation bill last year - the third-highest for Wellington-based MPs.
Asked about those expenses today, Mr Key said Mr Foster-Bell was among a group of MPs that tended to travel more, as that was required by the party.
"It's not unusual for us to use a list MP, certainly someone with skills like he has in foreign affairs, around the country. Other MPs ask him to support them in terms of talks or seminars ... or to fill in, for instance, for ministers."
Mr Foster-Bell was not available for interview. In a statement he said he believed his travel was within rules and for a Parliamentary purpose.
He would not provide details about what travel was funded last year.
Last night Newshub reported that Mr Foster-Bell had 12 staff leave in a period of three years, with one saying he was a "bully".
Other former staff said they left on good terms.
Mr Foster-Bell has two full-time positions funded for him, and it is unclear how many of the staff who left were employed part-time.
He would not clarify that or answer other questions about staff turnover or allegations of mismanagement, saying in a statement that "it would be inappropriate for me to discuss employment matters".
Mr Foster-Bell is 46th on his party's list and the negative press could worsen his prospects of holding or bettering that position.
He entered Parliament in May 2013 following the departure of Jackie Blue, and unsuccessfully contested the Wellington Central seat in 2011, Dunedin South in 2002 and Wellington Central again in 2014.
Mr Foster-Bell remained on the list after losing out in March 2014 to Shane Reti for National's nomination for the Whangarei electorate.