MP for Rangitata Andrew Falloon tendered his resignation from Parliament to the Speaker of the House this morning, effective immediately.
The Rangitata MP announced yesterday afternoon he would not stand in September's election.
Shortly after National Party leader Judith Collins put out a statement saying she was made aware on Friday afternoon of an issue relating to Falloon.
She went on to say Falloon was suffering from significant mental health problems and his privacy must be respected.
Falloon said the recent suicide of one of his friends has brought back much unresolved grief, that he had made a number of mistakes and apologised those who've been affected.
It is not clear why she said nothing about his behaviour towards the young woman and linked his departure to mental health.
RNZ has learnt Falloon sent the picture, which is not of him, to the 19-year-old woman after getting drunk.
The police had investigated but say it didn't meet the threshold for prosecution.
Falloon is the fifth National MP to announce they are quitting politics at the election in just over a fortnight.
