The House of Lords has refused permission to appeal in Chief Constable of Bedfordshire v Liversidge  IRLR 651.
The law is therefore settled. Under the Sex Discrimination Act 1975 and the Race Relations Act 1976, the Chief Constable of a police force is not liable for sex or race harassment upon a police officer by other officers in his command. (note: Liversidge dealt with the RRA, but the position was confirmed as identical for sex discrimination in Chief Constable of Cumbria v McGlennon (15/7/02).
The position with respect to race has been amended with respect to discrimination occurring after April 2001 (in which case, the chief constable is now liable) - but it remains the case that a female police officer cannot claim sex discrimination arising out of harassment by one of her colleagues.