Usher has hit back at a lawsuit accusing him of putting three people at risk of genital herpes.

The 'OMG' hitmaker was hit by a lawsuit last month from two women and a man who claimed he had put them at risk of the sexually-transmitted disease and he has now filed a response through his lawyers in which he denied their claims he had sexual contact with them or exposed them to herpes.

According to TMZ, Usher's lawyers, Laura Wasser and Zia Modabber insist the plaintiffs - only one of whom, Quantasia Sharpton, has come forward publicly - argued they can't win because they have ''unclean hands'', alleging they did something wrong, but not being specific as to what.

The response from the 'Yeah!' singer also insisted the group don't have a legal claim because anything he may have done was unintentional, suggesting that if he does have the infection - which he has neither confirmed nor denied - he didn't know it at the time.

He also argued that if he did have sex with any of them, they ''assumed the risk''.

The three alleged victims took legal action after it emerged the 'U Make Me Wanna' hitmaker had paid a woman $1.1 million in 2012 to settle a lawsuit after she claimed to have contracted herpes from .

The settled 2012 suit claimed Usher had been diagnosed with herpes around 2009 or 2010, but he was accused of ''consciously and purposefully'' withholding his diagnosis from the unnamed woman and ''continued to have unprotected sex'' with her.

And after coming forward about the lawsuit, Quantasia - who does not have herpes - recently claimed she took action against the 'Confessions' singer for not disclosing that he allegedly had the infection because she felt her ''rights were violated''.

She said: ''I had a child a year ago, and I knew I was negative. But I contacted [lawyer] Lisa Bloom to find out what my rights are as a woman.

''Although I am negative, I am upset by the reports because I never would have consented, if I would have known. I would not have taken a risk of getting an incurable disease.

''My health is very important to me, now that I am a mother. I feel that my rights were violated.

''I am speaking out today on behalf of myself and others, some of whom are positive and are embarrassed to speak out publicly. I am doing this so that he does not do this to anyone else.''

And the woman urged Usher to speak out and confirm whether or not he has the condition.

She added: ''Usher, if you are negative, please say so. If you are positive, you need to warn your sex partners, so that they can make their own informed decisions.''