Crash victim Larry Thomas had more than twice the legal amount of alcohol and a "fairly high amount" of cannabis in his bloodstream when he died, Supreme Court heard yesterday.

The evidence came from an expert who testified for the prosecution in the case against van driver Roger Bowen. He's accused of killing Mr. Thomas, 34, while driving over the alcohol limit himself in the early hours of April 26 last year.

Bowen, a 26-year-old air conditioning mechanic from Sandys, denies the offence.

Prosecutors allege he was driving west towards Somerset on Somerset Road and Mr. Thomas was driving east towards Hamilton when Bowen's van entered Mr. Thomas' lane and hit him. Mr. Thomas, a father-of-two who worked as a bartender at the Salt Rock Grill in Somerset, died of multiple injuries.

Yesterday, forensic toxicologist Susan Grosse told the jury the results of samples taken from 34-year-old Mr. Thomas' body after he died. He had 194 milligrams of alcohol in 100 millilitres of blood, which is more than double the 80 milligram legal limit for driving. He also had what she described as "a fairly high amount" of THC a chemical found in cannabis in his blood.

Dr. Grosse explained that in an average social drinker, amounts of alcohol in blood in the range of 100-200 milligrams per 100 millilitres cause disorientation and lack of co-ordination. She said that the presence of cannabis indicated that Mr. Thomas probably took the illegal drug in the three to four hours before he died. On its own, she said cannabis can cause drowsiness and poor co-ordination and can impair a person's ability to drive. However, studies show the effects of alcohol and cannabis are intensified when they are used in combination.

Earlier in yesterday's evidence, the jury heard from Police Constable Valerius Jean Louis, who was called to the scene of the collision around 3.08 a.m. He said Bowen told him: "I was coming up the road and he hit me." He smelled alcohol on Bowen's breath and noted that his speech was slurred, although Bowen denied he'd been drinking.

The officer arrested him on suspicion of impaired driving, with Bowen responding to the arrest by asking "why?". Asked for a breath sample at the scene he replied: "Why are you doing this?"

Bowen was taken to Hamilton Police Station where he consented to doing a breath-test, which was taken by Sergeant Carl Gibbons. Pc Jean Louis was about to outline the results of the tests when he was interrupted with an objection from defence lawyer Elizabeth Christopher. The jury has heard that Sergeant Gibbons is due to be called as a witness later in the trial. Bowen denies causing death by driving with excess alcohol. He also denies a second charge of driving with excess alcohol. The case continues.