Blues musician Fats Domino was rescued from New Orleans shortly after Hurricane Katrina hit, reports said.
Fats Domino has rarely appeared in public in recent years
His daughter Keren Domino White told CNN she had seen her father being helped off a rooftop in a newspaper photograph taken on Monday.
But Ms White said she had not been able to contact her father since then.
The 77-year-old singer of Blueberry Hill had been reported missing since the storm hit New Orleans, flooding the city and leaving thousands feared dead.
More than one million people were evacuated from New Orleans and the surrounding areas before the hurricane struck, but Mayor Ray Nagin has estimated that up to 100,000 people decided to stay in the city.
In a photograph in the city newspaper, the New Orleans' Times-Picayune, a man resembling Domino can be seen climbing off a rescue boat.
The musician's agent Al Embry had earlier said that nobody had seen Domino since he told people he was planning to "ride out" the storm at his low-lying home.
Domino's niece, Checquoline Davis, reportedly posted a message on an online bulletin board on Thursday pleading for information.
She reportedly wrote that Domino, his wife, their children and grandchildren "didn't get out" of the second floor of his house.
Mr Embry, who has worked with Domino for 28 years, said on Thursday: "I hope somebody turns him up, but as of right now, we haven't got anybody that knows where he's at."
The singer and pianist, whose real name is Antoine Domino, has sold more than 110 million records, including Blueberry Hill and Ain't That A Shame.
He had nearly 20 US Top 20 singles between 1955 and 1960.
Among the last of them was Walking to New Orleans, a Bobby Charles composition that became a string-laden tribute to the city that inspired him.
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Meanwhile, actor Nicolas Cage and singer Celine Dion have each donated $1m (£544,000) to the American Red Cross to help victims on the Gulf Coast.
Rappers Sean "Diddy" Combs and Jay-Z jointly donated $1m to the same cause while singer Hilary Duff gave $250,000 (£136,000) to hurricane charities.
Oscar-winning actor Morgan Freeman has set up an online auction.
The six major US TV networks are planning a joint live telethon to raise money for hurricane survivors, reports the Reuters news agency.
Plans are said to be at an early stage but the event is expected to be free of commercials.
A similar joint telethon was broadcast 10 days after the September 11 attacks. It attracted 59 million viewers and raised more than $150 million (£81m) in pledges.
TV news executives have said they will not shy away from showing graphic pictures of the aftermath of the hurricane, including images of dead bodies.
Senior figures at ABC News and Fox News were among those to tell the Hollywood Reporter they would not pull back from showing strong images but said they were considering issues about taste.
ABC has pulled its promotion of drama series Invasion, about a family coping with a fictional hurricane, for fear of offending viewers after Hurricane Katrina.
The channel said it may also delay broadcasting the series, due to begin on 21 September.