If you have been accused of a crime, you should always seek advice from an expert criminal solicitor before saying anything to the police.
Even if you think you have an innocent explanation for an allegation that has been made against you, the police may be withholding evidence from you, and you may unwittingly provide them with information that harms your interests.
An experienced criminal defence solicitor will not only know the law that applies to your case, they will often be familiar with the officers dealing with your case, and so will have a legal, tactical and psychological advantage when advising you. Also, when you have been accused of a crime it can be difficult to remain objective, and so an experienced and expert solicitor will bring a sense of calm and perspective when advising you on your best options.
Even if you think it is in your best interests to speak with the police, it may actually be better to say noting at all.