If my boss sue me for unfounded allegations, but its not true, what shd i do?

my boss's lawyer issued me a letter to ask me to write a letter saying that what i claimed is just a mistake and i was just spreading malicious comments about him.... i just doesnt know whether i shd write or should i report him to the police because of sumtin indecent that he did to me? this happen in singapore so... i wld like to know what category of the law this falls into.... tks