LOS ANGELES - Michael Jackson was a child prodigy, a musical genius and one of the most idolised artists on earth.

But for all his iconic status, the 50-year-old pop megastar -- who is expected to announce his first concerts in more than a decade on Wednesday -- risks seeing his legend overshadowed by paedophilia accusations.

While Jackson reigned as the "King of Pop" in the 1980s, his once-stellar career has been overshadowed by his colorful public behaviour, his startling physical transformation and multiple allegations of child abuse.

Jackson has lived as a virtual recluse since he was acquitted in 2005 on charges including child molestation and plotting to kidnap his young accuser.

Despite his acquittal, the trial was a body blow from which the pop music superstar has yet to recover.

Four years later, the 50-year-old is still worshipped by fans for revolutionising music, dance and music videos at the peak of his success.

The attention however paid to him in recent years has been less flattering, focusing on apparent cosmetic surgery -- which he denies -- his baby dangling antics and a decade of swirling child abuse allegations.

Born on August 29, 1958, Jackson made his show business debut with four of his older brothers in the Jackson Five pop group, and went on to lead the stage clan with a piping soprano and dazzling dance moves.

By 1969, the group had signed with Motown Records and became one of the last great acts to emerge from the legendary label.

The Jacksons produced seven singles for Motown that each sold more than one million copies and three albums which each sold more than two million. They moved to CBS's Epic Records in 1976.

Despite the success, Jackson recalled those years as unhappy and lonely ones. Eventually the family act broke up and Jackson went solo.

In 1979, Quincy Jones produced Jackson's first solo album for Epic, "Off the Wall," a huge disco-oriented success that sold 10 million copies.

They teamed up again in 1982 for "Thriller" which became the top-selling album of all time, with sales exceeding 41 million.

According to Robert Thompson, an expert in pop culture at the University of Syracuse, New York, Jackson's later problems can be traced to the phenomenal success of "Thriller."

"He got to the point that he was so rich, so powerful and so famous, that he was allowed to kind of withdraw from any kind of reality," Thompson told AFP.

"Thriller" was followed by "Bad" in 1987 (20 million sold) and "Dangerous" in 1991 (21 million sold) with videos whose auto-erotic dance contrasted with Jackson's sweet, childlike personality offstage.

In 1991 Jackson signed a deal with Sony Music described as the most lucrative contract ever for a recording artist. Although Jackson's share was not disclosed, Sony estimated the potential in sales at a billion dollars.

But in 1993, a 13-year-old boy made sex abuse allegations against his former pal Jackson and prosecutors launched an investigation.

A year later, Jackson struck an out-of-court agreement with the family under which he paid out 23.3 million dollars, a deal which Jackson has said he now regrets.

The deal halted the criminal case, which was being pursued by Tom Sneddon, the chief prosecutor in Jackson's trial.

As Jackson's life became more complicated, he also started undergoing a dramatic physical transformation.

Over the years, his skin has become much lighter and he appears to have had extensive plastic surgery on his face. Vanity Fair magazine reported in 2003 that the tip of his nose is actually a prosthesis.

In 1994, he stunned the public by marrying Lisa Marie Presley, the 26-year-old daughter of Elvis Presley.

The marriage lasted less than two years and was a hot topic for the tabloids. However, the renewed interest in Jackson's love life did not spark interest in his music.

In June 1995, he released the double album "HIStory, Past, Present and Future -- Book I" to negative reviews and weak sales -- despite Sony Music's 40-million-dollar investment. Jackson's next album, "Invincible," flopped.

Jackson then married Debbie Rowe, a 37-year-old nurse he met while undergoing surgery in 1997. They had two children, Prince Michael and Paris Michael Katherine, before divorcing in 1999.

Jackson had custody of the two children and of a third, Prince Michael II, born to an unknown woman, when in November 2002 he came under fierce public criticism for dangling his youngest child from a fourth-floor hotel balcony in Berlin for photographers.

Adding to his woes Jackson has also been hit by a flurry of lawsuits from former aides, promoters and others over alleged unpaid bills. Last November, Jackson and a Bahraini prince struck an "amicable" deal to avoid a London court case over a seven-million-dollar lawsuit.

A treasure trove of Jackson memorabilia, including a wrought iron gate from his Neverland Ranch and his famous white glove, are to be auctioned off in Beverly Hills, reflecting the singer's change in circumstances.