THE California Supreme Court has refused a request to delay the preliminary hearing in R&B singer Chris Browns assault case. The 19-year-olds lawyer requested the delay last week to gain access to police records. An appeals court had already rejected a similar request. The singer is due in court on 22 June for the hearing. Brown has pleaded not guilty to assaulting and threatening his singer girlfriend Rihanna in February. The preliminary hearing will determine whether there is enough evidence for the case to go to trial. Barbados-born singer Rihanna, 21, has been requested to appear as a witness. It is thought she is likely to testify in the case. Brown faces up to four years in prison if convicted of the charges. The singer is best known in the UK for the top 10 hits Run It, Forever and his duet with Jordin Sparks, No Air. - BBC