New Zealand's opposition leader caught using vulgar language

New Zealand's opposition leader has been secretly recorded calling one of his own lawmakers "f---ing useless" and making other questionable remarks as turmoil in the conservative National Party escalated on Wednesday.

Simon Bridges said he's apologised to lawmaker Maureen Pugh for making the inappropriate comment. Bridges said he has no intention of resigning after a former colleague accused him of corruption, initiated a police investigation, and posted the embarrassing phone conversation on Facebook.

Lawmaker Jami-Lee Ross resigned Tuesday after saying Bridges was corrupt because he hid a donation from a wealthy Chinese businessman by arranging for it to be split into smaller amounts to avoid it being publicly disclosed. Bridges deny the charge.

Ross went to the police Wednesday with what he claimed was evidence before posting the conversation with Bridges.

During the conversation, Ross tells Bridges that two men, including Zhang Yikun, have donated 100,000 New Zealand dollars (USD 66,000) and had expressed interest in having another Chinese lawmaker.

"Two Chinese would be nice, but would it be one Chinese and one Filipino, or what do we do?" Bridges ask. He talks about a possible "mercenary cull" and how he'd like two or three lawmakers to leave, including Pugh.

Bridges said Wednesday that while he might have been blunt, he was simply trying to reflect the growing diversity in the community.

"I'm not perfect, as that conversation shows. Perhaps I'm something of a rough diamond sometimes," Bridges said. "But I sleep well at night because I've got my integrity." He said Ross had been trying to set him up and may have been secretly recording him for months.

"He's a terrible person," Bridges said.

Ross said he believed Bridges had broken electoral laws and he'd handed over evidence to police investigators. He said he recorded the conversation because he was uncomfortable about the donations.

In a statement, police said they'd received a complaint and would provide any relevant updates in a timely manner.

The National Party held power for nine years before being ousted last year by a liberal coalition led by Prime Minister Jacinda Ardern.  

(With inputs from agencies.)