It has been reported that Bowie was cremated shortly after his death.
The Daily Mirror quoted a "US source" as saying that the singer, who died aged 69 after suffering from cancer for 18 months, was "secretly cremated".
The source said: "There is no public or private service or a public memorial. There is nothing."
The star's spokesman declined to confirm or deny the report.
Bowie will be honoured with a tribute at next month's Brit Awards, as well as a memorial concert at New York's Carnegie Hall on March 31.
Blackstar, released on January 8 to mark his birthday, looks certain to hold on to the number one spot in the charts on Friday.
It is also likely to be his first number one album in the US.
His death has seen an outpouring of grief from the public and from his friends and colleagues, including Madonna, Iggy Pop, Mick Jagger, Tina Turner and Paul McCartney.
Recording a SiriusXM Town Hall special on Wednesday night in front of a small audience, Elton John reportedly broke into a performance of Space Oddity as a tribute to his friend.
He then told moderator David Fricke: "It's so wonderful. We all know how inspiring he is. We all know that his music stands. We don't have to say anything about the music - it speaks for itself.
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"He was innovative, he was boundary-changing, and he danced to his own tune - which in any artist is really rare."
He added: "He made two albums without anybody knowing he was making them. He had treatment for his illnesses without anyone knowing or anyone saying anything.
"And that is the mystique of the man, because we know David Bowie the figure, the singer, the outrageous performer but, actually, we don't know anything about him - and that's the way it should be in music and should be in any art form whatsoever.
"They don't make them like that any more. We've lost a huge, huge talent that influenced so many people."
- PAA