A white racist who kept a haul of weapons and terrorised a "hit list" of people with threats to rape or torture them has been jailed for nearly five years.

Lukas Vongyer, 40, kept weapons including a samurai sword, crossbows, ammonia and hunting knives at his flat, Scotland Yard said.

He drew up "target list" of former employers and others he believed had done him wrong and bombarded them with racist emails and threats to harm them, police said.

Vongyer, of Wellesley Road in Gospel Oak, north London, also carried out a string of cyber attacks on their business websites, causing them to crash repeatedly, the Yard said.

In one case, he set up an email account similar to that of one of his victims and used it to send a message outlining plans to kill US President Barack Obama.

Police believe he did this in the hope his victim would be targeted by US secret services.

Investigating officer Detective Sergeant Ben Hobbs, of the Falcon Unit - the Met's cyber crime and fraud team, said: "Vongyer felt he had been wronged by his victims but his actions were not those of a disgruntled employee.

"He sent vile, racist emails threatening extreme violence against his victims and sometimes typed their home addresses in the emails to make the threats even more real. These emails left his victims feeling sick and terrified for their lives.

"It seems, from what we found in his flat, that he had put considerable time and effort into imagining what he saw as revenge against people who had employed him as many as 10 years ago.

"Thankfully, Vongyer never followed through with his threats."

Officers investigating the cyber crimes raided his flat on May 13 this year and discovered a sinister trove of deadly weapons and racist material.

They found detailed plans for racial cleansing written and sketched by Vongyer, freshly laundered camouflage clothing and boots in sealed packaging, and a handwritten "target list" featuring the names of his victims.

Bomb-making books and a bottle containing ammonia - believed to be intended for squirting acid at victims - were also found alongside a high-powered air rifle, hunting knife, samurai sword and arrows for crossbows.

Videos showing "extreme acts of violence" were found on his computer, which he had used to trawl the internet to research his victims, cyber attacks and bomb making tips, the Yard said.

Using a fake driving licence, he opened up a Bitcoin account to buy things on the so-called dark web, officers said.

In some cases, he demanded a ransom be paid for him to stop the cyber attacks and not carry out the violent assaults on his victims and their loved ones.

Vongyer was sentenced to four years and 10 months in prison at a hearing yesterday at London's Wood Green Crown Court, the Yard said.

He had earlier pleaded guilty to racially aggravated harassment with fear of violence, four counts of unauthorised act to a computer, blackmail, two counts of harassment with fear of violence and forgery.