The FBI has released shocking pictures of the horror dungeon where Briton Geoffrey Portway planned to rape, kill and eat children.

The room contained a home-made coffin, a steel cage and weapons to use against his victims.

The 40-year-old has admitted to his evil plotting and prosecutors want him jailed for 27 years. He is due to be sentenced on Tuesday.

Portway created the dungeon in the basement of his Massachussetts home, soundproofing it and double-locking it.

Court documents filed yesterday described his plans as some of the “most vile and heinous crimes” known to society.

The papers, obtained by the Boston Herald, said: “Portway has pled guilty to some of the most vile and heinous crimes known to our society, namely participating in the sexual exploitation of young children through the possession and distribution of child pornography and soliciting the kidnapping of a child for the purpose of killing and consuming that child.”

He had been in discussions with conspirators across the country, including sex offender Ronald Brown, jailed for 20 years in Florida this month for plotting to kidnap children through his local church.

The Boston Herald claimed that Brown had sent Portway a picture of a child with lines on it “to identify the different cuts of meat.”

It emerged in the court papers that Portway had used the alias Longpig - the cannibal name for human flesh - as he communicated with other paedophiles.

The FBI first began investigating Portway in 2012 after he was linked to an internet chat room related to cannibalisation and child rape.