David Blunkett is seeking international co-operation to shut down internet porn sites visited by murderer Graham Coutts.

The Home Secretary is in the United States for high-profile discussions with the Bush administration on combating terrorism.

But he also wants to gain backing for plans to block access to the types of violent sites viewed by Coutts, who killed Brighton teacher Jane Longhurst.

As reported in The Argus, Jane's mother, Liz Longhurst, and sister, Sue Barnett, presented a five-point plan to Mr Blunkett in London on Thursday.

Among their requests was for Mr Blunkett to make it a criminal offence to possess extreme images.

Mrs Longhurst will today join the Mayor of Reading, where she lives, and local councillors to launch a national petition calling for action to block extreme internet sites.

A Home Office spokeswoman said ministers were keen to secure "international co-operation" to ban the cyber-porn which fuelled Coutts's obsession with violent sex.

She said Mr Blunkett would meet US Attorney General John Ashcroft during the trip, in which he is expected to visit both Washington DC and Boston.

She said: "He will be raising with the Attorney General the issue of how we can co-operate to close down internet sites dedicated to matters such as necrophilia and adult violence.

"We believe effective action can be achieved only through international co-operation and want to start this discussion."

Special needs teacher Jane, 31, was strangled by Coutts with a pair of tights last March.

The 35-year-old killer, a salesman and part-time musician from Hove, had visited extreme porn sites the night before the killing.

He kept her body in a storage unit for 35 days before driving it to remote woodland near Pulborough, where he burnt it with petrol.

Coutts had trawled the internet looking at sites depicting rape, necrophilia and strangulation.