The Prime Minister says allegations about Winston Peters' handling of political donations do not stop him from performing his ministerial responsibilities.
The Dominion Post newspaper reported on Tuesday that the New Zealand First party accepted about $150,000 in anonymous donations from a prominent horse racing family.
The report followed an announcement by Mr Peters last Friday that his lawyer accepted $100,000 from a Monaco-based businessman, Owen Glenn, in 2006 towards the costs of an electoral petition.
Mr Peters had previously denied that his party received the money.
Mr Glenn was the Labour Party's largest donor at the 2005 election.
Helen Clark has faced questions about the Foreign Affairs and Racing Minister, including whether he was involved in negotiating tax breaks for the racing industry.
She says he does his job with integrity.
Mr Peters is attending an ASEAN conference in Singapore, but has dismissed the latest claims as unsubstantiated.