Updated

The fisherman who claims he survived for 13 months in the Pacific should return to Mexico to explain the death of a man who accompanied him, the victim's family said.

Jose Salvador Alvarenga said that the young man who accompanied him was a teenager who starved to death because he would vomit the raw fish and birds they ate.

According to AFP, the family of the victim, identified as Ezequiel, said they could not believe that he refused to eat.

"We want him to come here, for the government to bring him here," Ezequiel's brother, Romeo Cordoba Rios told the news service.

The family does not want a criminal probe against Alvarenga.

"It was a work accident," Cordoba Rios said. "The only thing we want is to know what was the last thing that he told this man and what he did with my brother's body."

The family told AFP that Ezequiel did not really know Alvarenga and decided at the last minute to join him aboard a small boat in 2012.

Alavarenga said Ezequiel died four months into the journey and that he pushed the body off the boat.

Some experts are challenging Alvarenga's claim that he miraculously survived 13 months at sea by eating fish, birds and turtles before washing ashore on the remote Marshall Islands 6,500 miles from Mexico.

"I may have some doubts," said Gee Bing, acting secretary of foreign affairs for the Marshall Islands, where Alvarenga washed ashore. He noted that Alvarenga looked thin when he was found, but he could walk on his own and was not as emaciated as might be expected considering how little he had to eat or drink.

Bing said island officials are investigating Alvarenga's story. The Telegraph reported that nobody reported him missing back home in Mexico, but investigators said the algae growth on the side of the boat indicates it had been in the water for some time.

Officials were reacting cautiously to the Spanish-speaking man's story while they try to piece together more information.

Mexico's Foreign Relations Department says the man told Mexico’s ambassador to the Philippines, Julio Camarena, that he set out from an area near the coastal town of Tonala in southern Chiapas state, which would mean his journey covered a distance of more than 6,500 miles, if he drifted in a straight line.

Ambassador Tom Armbruster in Majuro said the soft-spoken man complained of joint pain Monday and had a limp but was able to walk. He had long hair and a beard, the ambassador said, and rather than appearing emaciated he looked puffy in places, including around his ankles. Otherwise, he added, Alvarenga seemed in reasonable health.

Alvarenga said he left Mexico in his 23-foot fiberglass boat for a day’s fishing, accompanied by Ezekiel.

A storm blew the fishermen off course, and soon they were lost and adrift.

After about a month, Ezekiel died, the survivor told officials.

Alvarenga also talked about eating turtles. Once near Ebon, he swam ashore.

The Associated Press contributed to this report.