Hone Harawira says he has no concerns about the Speaker looking into exactly what he did on his taxpayer-funded trip to South Africa.
The Speaker is to ask Mana Party leader to clarify what he did there during the mourning period for Nelson Mandela.
Mr Harawira, a prominent protester against apartheid in the 1980s, travelled to Johannesburg and Pretoria separately from New Zealand's official delegation to represent the protest movement at Nelson Mandela's official memorial service.
Yesterday, Prime Minister John Key questioned Mr Harawira's decision to go to South Africa, saying many people could have played a stronger role than the Mana leader.
"This is a guy who has barely turned up to Parliament in 2013. This is a guy that went to South Africa on a 'jolly' and actually shouldn't be billing the taxpayer for it."
Mr Harawira's request to use his parliamentary party leader's budget to fund the trip was approved by the Speaker's office.
But a spokesman for the Speaker said David Carter would write to Mr Harawira asking him to explain his version of events after it appeared that the Mana leader might not have attended official events in South Africa.
Mr Harawira told Radio New Zealand the parameters to use funds from his leader's budget were clear - "that the visit has to have a parliamentary purpose".
"Clearly it was to attend the same activities that the Prime Minister attended. The Speaker approved the funding and so I went."
He said he attended a "major memorial service" held in Soweto, saw Mandela lying in state, and attended a small, private service held at the home of Mandela's family where he performed a haka.
"On top of that, we visited the museum of apartheid, and met with church leaders and anti-apartheid activists from all around the world.
"I think we achieved the purpose of representing well the anti-apartheid movement and Maori and Pacific Island people who were key to that anti-apartheid movement back in 1981."
A spokeswoman for the Te Tai Tokerau MP said the travel costs of his wife, Hilda, were met by private donors who wanted anti-apartheid protesters to attend the service.
Newstalk ZB reported that Mr Harawira reacted angrily to questions about his wife's travel.
He pointed to the $100,000 cost of sending the official New Zealand delegation which included Mr Key, Opposition Leader David Cunliffe, Maori Affairs Minister Pita Sharples, former prime minister Jim Bolger and former foreign affairs minister Sir Don McKinnon.
Mr Harawira had criticised the selection of the group because the activists whom Mandela had recognised as playing a role in ending apartheid were absent.
Mr Key defended the delegation yesterday, saying there was limited space and the "right mix" of people had been chosen.
*Attended inter-church memorial service for Mandela in Soweto.
*Visited Mandela's house and performed haka.
*Saw Mandela's body lying in state in Pretoria.
*Attended public- housing and shack dwellers' meeting in Durban.