Attorneys for accused Tucson shooter Jared Loughner on Monday again filed court papers challenging an order that allows him to be forcibly medicated in prison.

Loughner, 22, in May was declared mentally incompetent to stand trial on charges that in a January shooting spree he killed six people and wounded 13 others, including U.S. Representative Gabrielle Giffords who was shot in the head.

The 32-page filing by Loughner's defense attorneys on Monday is the latest salvo in a legal battle over a decision by officials at a Missouri prison where he is being held to forcibly give him anti-psychotic medications.

Loughner's attorneys said his due process rights were violated by that decision and argued officials have minimized the "severity of the intrusion on Mr. Loughner's liberty by characterizing the psychotropic drugs as 'positive.'"

They also objected to a prison warden's finding that Loughner could damage property if he is not medicated.

"It is plainly erroneous to uphold forcible medication on the basis of risk of harm to mere property, and the error affected Mr. Loughner's substantial rights, and the fairness and integrity of the proceedings, because it resulted in his bodily and mental integrity being violated by brain-altering chemicals," Loughner's attorneys wrote.

A federal judge in June rejected an attempt by Loughner's attorneys to prohibit Loughner's forced medication. In July, the 9th U.S. Circuit Court of Appeals put Loughner's medication on hold, until attorneys could fully litigate an appeal of the lower court ruling.

But the appeals court changed direction later in July and allowed Loughner's forcible medication while the case is on appeal. Prosecutors have said Loughner poses a danger to himself and others and that his mental condition deteriorates after medication is stopped.

A hearing is scheduled in front of the 9th Circuit on August 30 in San Francisco.

Loughner, a college dropout, has pleaded not guilty to numerous charges, including first-degree murder, stemming from the January shooting spree.

The shooting occurred at a gathering of constituents that Giffords held at a Tucson supermarket.