The brother and sister of convicted serial killer Robert Pickton are suing the attorney general and solicitor general of British Columbia for damages resulting from the search of the farm where RCMP found the remains of six murdered women.

The lawsuit, filed by David Pickton and Linda Wright, claims the RCMP search of the farm where Pickton lived in suburban Coquitlam destroyed equipment and terrain the siblings had lawful rights to use.

"As a result of the said actions by the RCMP, the properties are presently useless and the plaintiffs have suffered significant loss and damage," in a statement of claim filed this week in B.C. Supreme Court.

"The RCMP disturbed, disrupted, killed and destroyed various plants, trees, groundcovers and other vegetation and the fish in the pond on the properties."

Pickton's siblings further claim the search excluded them from properties they had a legal right to use and they accuse the RCMP of demolishing, removing, destroying or rendering uninhabitable various buildings and equipment on the property.

"The actions of the RCMP aforesaid were done in violation of the rights and interests of the plaintiffs, or alternatively were done negligently."

The two Pickton siblings, who owned the property jointly with their brother, are seeking damages, cost and interest from the province.

They say they were promised compensation for damages but haven't received any.

David Pickton declined comment Thursday.

A spokesman for Attorney General Wally Oppal said his department hadn't yet seen the statement of claim and could not comment Thursday. RCMP also declined comment.

The province has a $10-million lien on the property to secure recovery of legal costs for Pickton's trial.

Friends and family of the murdered women have said they'd like the property turned into a memorial park.

Forensic experts and archeologists spent months combing the 4.5-hectare property, uncovering gruesome evidence, some of which was presented at Pickton's trial.

Pickton was convicted in December 2007 on six counts of second-degree murder following an 11-month trial and several years of pretrial arguments.

Pickton is now serving a minimum 25-year prison term for the murders of Mona Wilson, Marnie Frey, Georgina Papin, Brenda Wolfe, Sereena Abotsway and Andrea Joesbury.

The B.C. Court of Appeal is set to hear arguments in the case starting March 30.