DALLAS (Bloomberg) — Lawyers for workers suing BP Plc over injuries from a 2005 explosion at a Texas refinery stepped up efforts to take testimony from John Browne, who resigned May 1 as BP's chief executive officer.The attorneys asked a judge to find Browne in contempt of court for failing to obey a court order to testify. The Texas Supreme Court delayed Browne's deposition earlier this year after he said he knew nothing about the blast and was too busy to give testimony on what led to the explosion. The workers' lawyers said today those arguments no longer apply.

"Now he's no longer CEO," lawyer Brent Coon told state Judge Susan Criss at a hearing in Galveston, Texas. "And his affidavit that he has no personal knowledge of the explosion should be stricken, because Browne is an admitted perjurer." Browne "lied to the High Court in London," Coon said.

BP, Europe's second-largest oil company, faced more than 3,000 injury and property claims from a 2005 explosion at its Texas City, Texas, refinery, which killed 15 people and injured hundreds. The company so far has avoided trials by settling about 1,350 claims. About 120 are set for trial later this year.

Browne, 59, resigned as CEO of the company after losing a UK court fight to block publication of a newspaper story detailing his affair with a Canadian man. In a decision allowing publication of the story, the London High Court said Browne lied under oath about details of the affair.

"That issue is completely irrelevant to what's going on" in the Texas explosion cases, BP's lawyer Katherine Mackillop told Criss today. Mackillop said the personal details about which Browne perjured himself in London "have nothing to do with the Texas City explosion."

"I'm not resting assured" the issues are unrelated, Criss replied. "Chances are if he lies in one court, he lies in another. But we just can't assume that."

Criss didn't rule on the workers' May 9 motion to find Browne in contempt for not obeying her order to give sworn statements in the blast cases. The judge asked the workers' lawyers to research whether she has authority to override the Texas Supreme Court's stay of Browne's deposition if the facts on which the delay was based have changed.

"You're going to have to show me some case law that says I can," Criss told the lawyers.

BP spokesman Neil Chapman said the company will continue to fight the order on behalf of its former CEO. "The stay continues from the Texas Supreme Court, and Lord Browne has no unique knowledge" of what led to the explosion, Chapman said in an interview outside the court.

The explosion occurred when an octane-boosting unit overflowed as it was being restarted. Gasoline vapours leaked into an inadequate vent system and ignited in a blast that was felt five miles away.

A report in March by the US Chemical Safety Board said corporate budget cuts compromised worker safety at the plant.