When Sir Stephen Tumim, the respected former inspector of prisons in Britain, visited Hong Kong's jails last year, he praised the good system of control, which he said helped to reduce bullying and fighting between inmates. But control systems are always in danger of being over-zealously applied, particularly at times of heightened tension. The internal inquiry into the fight at Ma Po Ping prison last month concludes that the force used was necessary in trying to separate the combatants. What blame there is is levelled at the prison management for failing to prepare for the potential outbreak of trouble. As police are investigating allegations of assault by CSD officers, the findings released yesterday were only presented in general terms. This is unfortunate, because on present evidence it looks suspiciously like a whitewash. When 78 prisoners file complaints about excess force, some claiming to have been beaten after they sat down, it seems unlikely that every one of them is concocting a story, even though some might well use the incident to settle a grudge with an officer, or to cause trouble for the staff. Nineteen prisoners were injured in the fracas, as well as two CSD officers. That is a large casualty list for a situation in which order was quickly restored. As always in such matters, the lack of independent investigators reduces the authority of the report. The findings might be more readily accepted if they were compiled by a team which included people of standing from outside the prison service. Any organisation which acts as judge and jury in an inquiry into its own actions, is inviting some scepticism from the public at large. That is the way it is with the police, and so it is with the prison service. Whatever argument can be advanced about fellow officers understanding the workings of the system, the counterweight of public accountability is equally valid. Prison staff have a difficult job, and for the most part do it well, but abuses do occur, and they cannot go unpunished. The real problem in local jails is overcrowding, which increases stress on staff and inmates alike. Better facilities, more education for inmates, and an improved environment would lead to a calmer atmosphere.