NSW Energy Minister Chris Hartcher has quit his portfolio over the issue of a search warrant by the Independent Commission Against Corruption (ICAC).
In a statement on Wednesday, Mr Hartcher said he would continue to serve as member for Terrigal, on the NSW Central Coast.
"I am confident I will be cleared of any wrongdoing," he said.
"This is the first contact I have had with the ICAC and given that their investigations have thus far had an unknown timeframe, it is appropriate that I resign."
Mr Hartcher said it would not be appropriate to comment further while the matter was before the ICAC.
In September, ICAC officers reportedly searched the Central Coast offices of Chris Spence and Darren Webber.
Media reported computers and documents were seized in relation to claims of irregularities in donations to the Liberal Party on the Central Coast.
A senior staff member of Energy Minister Chris Hartcher, Tim Koelma, resigned last year and his electorate officer Ray Carter was suspended over the allegations.
Mr O'Farrell said he spoke to Mr Hartcher from India, where he is on a trade mission.
In a statement, the premier said he supported Mr Hartcher's decision to resign.
"I accept and support Mr Hartcher's decision to resign from cabinet following today's actions by ICAC," Mr O'Farrell said.
"Mr Hartcher advised me he is confident he will be cleared of any wrongdoing.
"However Chris said that, while the investigation is ongoing and in the interests of the government, he feels it appropriate to resign from the ministry."
Mr O'Farrell thanked Mr Hartcher for his service to the government and the state, "in particular for his success in bringing electricity prices under control".
