An RAF doctor facing charges over his refusal to serve in Iraq has told a court martial that he disobeyed orders "as a duty under international law".
Flt Lt Dr Malcolm Kendall-Smith was based at RAF Kinloss in Scotland
Flt Lt Malcolm Kendall-Smith, 37, who was based at RAF Kinloss in Scotland, has already served twice in Iraq but last year defied an order to return.
He claimed his actions were justified as the UK involvement was illegal.
A judge said the issue was not relevant to the case but the officer insisted he needed to cover it in his defence.
However, Dr Malcolm Kendall-Smith was rebuked by Judge Advocate Jack Bayliss during the hearing when he tried to read from his personal research into the Iraq conflict.
The officer denies five charges relating to his deployment to Basra, training and equipment fittings in June and July last year.
Opening the case for the prosecution, David Perry contended Dr Kendall-Smith did not have the "responsibility" to question the legality of orders given to him.
"The presence of British forces was not unlawful and as a regular serviceman he could not pick and choose those orders he did or did not wish to obey and no question of any unlawful order being given to him arises in this case," he told the Aldershot hearing.
He said the officer applied for early release from the RAF in May 2005 but was informed he would normally be expected to serve about another 12 months.
"The background to this case appears to be a sense of grievance felt by the defendant, firstly that he could not immediately resign from the RAF, and secondly that he remained eligible for deployment overseas," Mr Perry said.
Dr Kendall-Smith, who holds dual British and New Zealand citizenship, is the first officer to challenge the legality of the Iraq conflict at a court martial.
When interviewed after refusing to go to Iraq, he told the RAF he had considered the legal advice given to the prime minister and other reports.
Giving evidence at the hearing, he denied the prosecution claim he had submitted a resignation letter prior to being told of his deployment to Iraq.
He said he wrote a letter of resignation only after receiving verbal notification.
"I refused the order out of duty to international law, the Nuremberg principles and the law of armed conflict," he told the hearing.
He said his opinion on the illegality of the war was formed in June 2004.
"I was subjected, as was the entire population, to propaganda depicting force against Iraq to be lawful but it was not until the middle of 2004 that I had researched and found that not to be the case."
The case continues on Wednesday.