OAKLAND — The family of Jerry Amaro III, who died a month after suffering broken ribs from an alleged police beating in 2000, filed a $10 million civil-rights lawsuit against the city in federal court Tuesday.

The lawsuit follows revelations last month that the FBI is conducting an investigation of the incident, including the role played by then-Lt. Edward Poulson, who was later promoted to captain and became head of the department's Internal Affairs Division in 2008. Poulson was placed on paid leave Jan. 22.

Attorneys John Burris and Jim Chanin said Amaro was the victim of excessive police force, but also said that a number of officers conspired to cover up the facts surrounding his death, and to conceal information from Amaro's family and the public.

"The one group that did not know, who had the most vested interest, was the family," Burris said. "No one ever said to the family that, 'We now believe that officers wrongfully killed your son, your brother, and have not come forward.'"‰"

Amaro, then 35, was arrested on suspicion of attempting to purchase drugs from an undercover police officer March 23, 2000. Poulson used excessive force during the arrest, including kicking Amaro in the rib cage while Amaro was on the ground, the lawsuit says.

Amaro suffered five broken ribs and a lacerated lung, among other injuries, the lawsuit says. He was not provided medical treatment and instead was taken to jail after his arrest, the lawsuit says.

Amaro's mother, Geraldine Montoya, 62, and his sister, Stephanie Montoya, 23, of San Leandro, said Amaro went to a medical clinic on three occasions over the next month, but died April 21 of pneumonia caused by fractured ribs and a collapsed lung, according to a coroner's report.

"There's nothing in the world that can bring my son back," Geraldine Montoya said. "Nothing. Nothing can ever bring him back. "... Why should we have this in Oakland? Why should we have this cover-up?"

A spokesman for City Attorney John Russo declined to comment, citing an office policy against commenting on lawsuits that hadn't been reviewed. The lawsuit names the city of Oakland, Poulson, former police Chief Richard Word and six other police officers.

Acting police Chief Howard Jordan declined to comment on the lawsuit, saying he had not seen it. Jordan also said he had no details about the FBI investigation, and that the department completed an investigation of the Poulson matter eight years ago.

Administrative charges were sustained against Poulson for interfering with an Internal Affairs investigation, but then-Chief Word changed a recommendation to fire Poulson to a two-week suspension.

Former Chief Wayne Tucker put Poulson in charge of Internal Affairs in 2008. In January, when Tucker announced his decision to resign, he said he would have fired Poulson had he been in Word's position. He nonetheless said Poulson was the best choice last year for the Internal Affairs job.

Tucker's resignation came as members of the City Council were moving toward a vote of no-confidence in his leadership partially because of the Poulson matter.

For Amaro's family, the recent revelations offer a glimpse of what might have happened after suffering years of loss. Geraldine Montoya said that after her son's death she tried repeatedly to find an attorney.

"I faxed letters, everything," she said. "They called me and said they couldn't do anything about it. The door was closed. All the doors were closed."

Burris and Chanin said their lawsuit stemmed directly from news of the FBI investigation, which was first reported by The Chauncey Bailey Project.

"There's a lot we don't know," Chanin said. "We're going to do everything in our power to get to the bottom of this, so the family will know and the public will know who did what to Mr. Amaro."

The Chauncey Bailey Project contributed to this story. Reach Kelly Rayburn at 510-208-6435.