Canberra: Australian shooter and dual Olympic gold medallist Michael Diamond could be in doubt for the Rio Olympics after he was arrested on the weekend and charged with drunk-driving and firearm-related charges. The 44-year-old Olympic gold medallist at Atlanta in 1996 and Sydney in 2000 has had his driving license suspended after he refused to undergo a roadside breathalyser test on Saturday night, reports Xinhua. Officers then searched his vehicle, in which they found a shotgun and 150 rounds of ammunition. He was then taken into custody, where he returned a breath test reading of 0.159 -- more than three times the legal limit. Diamond was later charged with high range drink-driving, not keeping a firearm safe, and handling or using a firearm while under the influence of alcohol. He will reportedly face court next month, and despite being selected in the Australian shooting team which will head to Rio in August, could be axed. His spot in the squad was already in doubt after 16-year-old Mitchell Iles filed a challenge to the Court of Arbitration for Sport that he shot an Olympic benchmark score, which, if successful, would push Diamond out of the team. Diamond is widely regarded as one of Australia's most successful shooters, having made his Olympic debut in Barcelona in 1992. If he makes the trip to Rio, it would be Diamond's seventh Olympic campaign -- making him just one of two Australians who have competed at seven different Olympics.