A TEST case which could result in more than 250 convictions for drink-driving offences being overturned started at Basingstoke magistrates' court this week.

The case centres around an Intoximeter, which measures the proportion of alcohol in the breath, used for about 32 months at Whitchurch and Andover police stations. The particular model was found to be using a different variation of the approved software.

District judge Gareth Cowling heard that Richard Willis, 31, of Middle Wallop, was tested with the machine on August 3 last year and it read he was three times the legal limit. He has pleaded not guilty to drink-driving.

Adrian Fleming, representing Mr Willis, did not question the reliability of the reading but argued that under the Road Traffic Act 1988 the model of the Intoximeter was not approved and therefore the samples were not admissible.

"If someone were to say it's the same as the one that has been approved and it works just as well, one is simply driving a coach and horses through the whole purpose of the Road Traffic Act," he said. "If that's the case, we'd go back to the days of asking someone to walk in a straight line and say that is admissible."

However, Giles Cockings, prosecuting, said the difference between the Andover Intoximeter and the approved machine did not make any difference in this case and that the purpose of the act was to ensure consistency across the country.

The intoximeter was in operation between December 24, 1998 and August 9, 2001 at Andover, except for June and July 2000 when it was moved to Whitchurch police station. The Crown Prosecution Service's Special Casework Unit for Hampshire and the Isle of Wight has so far traced 260 drivers who may be affected by the outcome of the case.

The case was adjourned to a later date.