Michael Jackson used alcohol and pornography to seduce and molest a cancer-stricken boy, the prosecution told a jury as the case against the pop star began here.

Thomas W. Sneddon Jr., the Santa Barbara county district attorney, alleged Monday Jackson and his associates conspired to convince the boy that he and his family were in danger. This was done to compel them to appear in a 2003 documentary by British journalist Martin Bashir to rebut the charges against the pop star.

But Jackson's defence attorneys said in their opening statement that the accuser's family had laid a trap to get money from Jackson.

The prosecutors claimed that in order to silence the boy's family, Jackson flew them to Florida on a private jet, gave expensive gifts and detained them against their will at his Neverland ranch.

Sneddon alleged that one of Jackson's associates destroyed a urine sample the boy had prepared for his doctor because it would provide evidence that Jackson had given the boy alcohol before molesting him.

The charges were contained in a 10-count indictment against Jackson that was officially unsealed for the first time Monday.

Sneddon alleged that Jackson used his wealth and fame to lure young boys. He said detectives who searched the ranch in late 2003 found pornographic magazines that depicted young teenagers and as well as magazines from the 1960s showing naked children.

Sneddon acknowledged that the boy's mother had lied under oath in a lawsuit and had fraudulently obtained welfare benefits.

However, he explained that the mother's behaviour was a reaction to an abusive relationship with her former husband.