A former top lawyer for Toyota in the US has asked a federal appeals court to throw out a US$2.6m settlement he was ordered to pay to the automaker, saying the order violated his constitutional rights.

Dimitrios Biller had been a senior product liability lawyer for Toyota and managed the automaker's defence in a number of rollover accident cases, Reuters noted.

He resigned in 2007 after saying he had confronted the Japanese automaker about what he described as an effort to withhold evidence in legal cases stemming from accidents in Toyota vehicles.

His ongoing legal dispute with Toyota shot to national prominence in late 2009 and early 2010 when the Japanese automaker came under fire for not acting more promptly to address claims of unintended acceleration in its vehicles.

Biller said in a filing with the US Court of Appeals for the Ninth Circuit dated 2 August that he had sold his family house to pay $217,000 to Toyota. He said he still owes "approximately $2.4m" to the automaker under the terms of an arbitrator's ruling.

Biller and Toyota reached a severance agreement in 2007. But in late 2008, the automaker sued Biller in California state court claiming that he had improperly disclosed confidential information stemming from his work with Toyota in running a trial consulting business he had set up.

Toyota then won a preliminary injunction against Biller in California state court. Biller responded with his own lawsuit against Toyota in federal court, accusing the company of defamation and fraud.

In January 2011, an arbitrator appointed by the federal court sided with Toyota, ordering Biller to pay the automaker $2.6m.

In his filing with the federal appeals court, Biller called a ruling by a federal court judge upholding the judgment against him "a travesty of justice," saying that Toyota's severance agreement with him should have been subject to protections under California state law.

Biller said Toyota had been allowed by the court to take custody of his computer files under the terms of the order against him, including data on his clients other than Toyota.

Separately, Toyota faces a lawsuit from consumers in California who claim that their vehicles lost value because the automaker failed to address problems that caused some of its vehicles to surge forward. Toyota disputes that claim.

Toyota has in recent years recalled millions of vehicles for gas pedal and floor mat problems that owners have linked to unintended acceleration.