Metal band Slipknot 'upset by grave theft'

Pictured without their trademark masks Slipknot's Corey Taylor and Shawn Crahan

Metal band Slipknot say they're "upset" after gifts left at the grave of bassist Paul Gray, who died earlier this year, were taken.

Writing on their website the band said "statues of a gargoyle and a Buddah" had disappeared.

They appealed for the return of the items "no questions asked" and requested any information.

Gray, 38, died in May 2010 of an accidental morphine overdose.

The musician's unexpected death has left the future of the Iowa-based band uncertain.

In the same statement the band thanked fans for their "continued support in this trying time".

Tributes to Gray were held at last summer's Download festival and rock magazine Kerrang's! annual awards in August.

Slipknot's last studio album, All Hope Is Gone, debuted at number one in the US Billboard charts in 2008.