An online petition campaigning to help Michael Douglas and his ex-wife visit their imprisoned son has been removed.

Activist Tony Papa of the Drug Policy Alliance (DPA) started the petition on earlier this month, to highlight the need for prison reform in the U.S. and help Michael, 68, try to see his son, Cameron Douglas, who is being held in solitary confinement at the Federal Corrections Institute in Cumberland, Maryland, for drug offences, and isn't allowed to have visitors, but he has now deleted the campaign.

A DPA source told gossip website that officials had ''a change of heart'' because they worried the organisation would be accused of trying to help famous people get special treatment.

The online petition was removed shortly after Cameron's mother Diandra Luker, appealed to her celebrity friends, including Calvin Klein, Yoko Ono, Bianca Jagger and Bo Derek, to get behind the campaign for them to see their troubled son.

Cameron was handed a five-year sentence for heroin possession and conspiracy to distribute narcotics in 2009, which was extended by four and a half years in 2011 after he committed drug infractions behind bars, meaning he is due to be released in 2018.

Michael, who is trying to get his marriage to Catherine Zeta-Jones back on track, previously admitted he is desperate to be reunited with his son.