Questions were today being asked whether the identity of John Jones, a baby who died at just one-month-old, was used by Darwin after he was presumed dead.

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John Jones was born on March 27, 1950, at his gran's home in Sunderland. He died five weeks later from enteritis.

Now, his sister, Frieda Woods, 55, who still lives in Sunderland, said: "I feel terrible, it's such a shock.

"My parents always used to speak about John and told us he'd died barely a month after being born. He was premature and underweight. In those days they couldn't do as much for babies like that."

Cleveland Police confirmed they were looking at the use of the name John Jones as part of their inquiry.

It has been claimed Darwin, 57, used a fake identity on trips to Gibraltar and Spain in 2005 and last year to travel to Panama City and Costa Rica with wife Anne, 55.

Darwin, from Seaton Carew, is accused of making an untrue statement to procure a passport and dishonestly obtaining £25,000.

John Jones was the son of river worker Alfred Jones and his wife Lily. Buried on May 3, 1950, his body now lies in Ward 2, Section A of a Sunderland cemetery.

The spot is marked by a plain white plaque and mass of leaves.

Information has flooded in during recent days from around the world after police released a photo of Darwin showing him with a beard.

The former prison worker disappeared following an apparent canoe tragedy in 2002. His sudden resurfacing has made headlines around the world in recent days.

Mrs Woods, who still lives near the cemetery where John Jones is buried, said: "My parents are now dead, but they never forgot him. John was their first born, he was the eldest of nine."

The baby was born five months before John Darwin was.

Mr Darwin's wife Anne, appeared before magistrates yesterday accused of dishonestly obtaining £162,515 with claims on insurance and mortgage cover.