SPEED demons are using girls as young as 12 as ''prizes'' in illegal road racing contests, according to the head of the Anti-Road Racing Unit. Inspector Dave Bennett said organised racing, sometimes with more than money at stake, was still a major problem in the New Territories despite 33 prosecutions of road racing cases so far this year, compared with only seven in 1992. ''Our intelligence suggests that there is triad involvement with bets of up to $1 million, but if a race isn't for money then a female passenger will often be the first prize, with the winner getting the girl,'' he said. Of the 168 males convicted of illegal road racing this year, most were in the mid-20s to early-30s age group, while the 30 females convicted were between 12 and 20. Inspector Bennett said: ''Road racing is basically a machismo thing and older male drivers often lure young girls who are looking for a 'buzz' into being their passengers. ''We sometimes find girls as young as 12, and many aged 13 or 14, when we stop speeding cars in the early hours of the morning. ''But although we know these girls are often used as the 'prize' in races it is very difficult to prove because when they are questioned they deny everything.'' During an anti-road racing operation last week more women than men were arrested after two high-speed chases through Tai Po - a current hotspot for road racing activities. In the first, in Ting Kok Road the two male drivers were aged 25 and 27, while the three female passengers were aged between 19 and 21. In the second, four men, including the two drivers, and four women passengers, all aged 18 to 21, were arrested. Inspector Bennett added: ''We sometimes stop cars with a 30-year-old man driving and a 12-year-old girl in the back which is obviously suspicious, although it is virtually impossible to prove what is going on.'' With the Macau grand prix coming up on Saturday, police are bracing themselves for an increase in illegal road racing in the run-up to the event. But the Anti-Road Racing Unit, which was set up in 1985 to combat the road racing menace, is convinced that it has the problem under control, with about 1,000 prosecutions for traffic offences already this year. ''We have been very successful in cracking down on road racing so far this year and I believe we have justified our existence by acting as an effective deterrent,'' Inspector Bennett said. But with only an inspector, a sergeant and six constables, the unit is short of manpower as well as other resources. Inspector Bennett said: ''The unit has no special equipment and we are given standard police bikes and cars to chase racers in high-powered vehicles which makes our job very difficult. ''The vehicles we have are wearing out and not being replaced, while we simply don't have the manpower to investigate connections with organised crime.'' But Inspector Tobi Lothian, who took over from Inspector Bennett as head of the unit yesterday, , hopes to keep up the team's high profile and the momentum of arrests and prosecutions. ''Road racers often reach speeds of up 160 km/h and we cannot let them do this with impunity. We will continue to give chase and catch them,'' he said.