A Manhattan doctor is accused of covertly slipping the Plan B emergency contraceptive pill into his girlfriend's drinks to prevent her from getting pregnant, according to a lawsuit the woman filed in Manhattan Supreme Court.

Neuroradiologist John Nwankwo Ikechi, 37, allegedly admitted to drugging his girlfriend Hyosun Kim, 36, after she found an empty Plan B box in his trashcan and confronted him about it, the $5million lawsuit claims.

Ikechi 'confessed that he was aware [Kim] would never have voluntarily agreed to take the Plan B pill and told her that this was the only way he could get her to ingest' it,' the New York Post reports.

Neuroradiologist John Nwankwo Ikechi, 37, is accused of covertly slipping the Plan B emergency contraceptive pill into his girlfriend's drinks to prevent her from getting pregnant

Ikechi's then-girlfriend Hyosun Kim, 36, found an empty Plan B box in his trashcan last May and confronted him about it. Kim is now suing him for $5million

The couple had been dating a month when Kim, who was not taking birth control pills at the time, found the discarded box last May.

She 'was horrified that her boyfriend would deceive her in this way', so she broke up with Ikechi and 'sought medical treatment' for the stress the relationship caused her, court papers said.

Ikechi's 'conduct was so extreme and outrageous and exceeded the bounds of human decency', the lawsuit claims. As a doctor, he 'knows that an individual cannot be forced to ingest medication without his or her consent'.

Plan B is essentially a high dose of the ordinary contraceptive pill.

In the first two days after conception, it is 95 per cent effective. This drops to 58 per cent within 48 to 72 hours after unprotected sex.