TAIPEI, July 28 (AP) -- Taiwanese prosecutors on Friday indicted a man for murder, alleging he helped his brother stage a train derailment that ultimately led to the death of his brother's wife, and said they will seek the death penalty.

The wife of Lee Suan-chuan, a train ticket seller, was injured when the train she was traveling on derailed and tumbled into a deep valley on March 27 in southern Taiwan's Pingtung region.

She died the same day in a hospital after her husband allegedly put snake poison in her intravenous drip, prosecutors claim.

A week later, Lee committed suicide after police raided his home and barred the cremation of his wife's body, suspecting the derailment and the woman's death resulted from foul play. The suspects allegedly placed foreign objects on the railway tracks.

Prosecutors said Friday they were indicting Lee's brother, Lee Tai-an. They suspect the brothers had conspired to kill Lee Suan-chuan's wife to collect money in an insurance scam.

An earlier alleged attempt to injure Lee Suan-chuan's wife in a train derailment in June 2005 failed, prosecutors said.

Pingtung Chief Prosecutor Yeh Li-chi told The Associated Press that the death penalty would be sought against Lee Tai-an, who was arrested early last month, but has denied any involvement.

Prosecutors will demand a six-month prison term for another suspect, Huang Fu-lai, Yeh said. They said he was initially involved in the conspiracy but later changed his mind.

Lee Suan-chuan had made himself the beneficiary of a 20 million New Taiwan dollars (US$610,000; €510,000) insurance policy he purchased for his wife, prosecutors said.

He had been riding in the same carriage with his wife, but left it to buy a newspaper in another car shortly before his wife's carriage and three others tumbled into a steep valley.

Lee Tai-an's attorney, Wu Han-chen, maintained his client's innocence. "We will go to court to check how much evidence the prosecutors can offer," Wu said.