Peter Francis-Macrae, who lives in a Victorian cottage with his father and brother, runs a junk e-mail empire stretching from Cambridgeshire to China.

The exact scale of his vast spamming operation is incalculable, but he is suspected of having access to millions of e-mail addresses to promote a variety of products.

Most recent accounts filed at Companies House showed his business had a turnover of £49,000, but his income is understood to have risen well into six figures. When people on the internet challenge his methods, they complain that their computers are “bombed” with between 1,000 and 5 million e-mails.

After he was arrested and bailed by Cambridgeshire Constabulary on an unrelated allegation of deception, a hoax e-mail was sent around the world threatening to remove £400 from people’s bank accounts to pay for an iPod digital music player.

The contact number listed was the county’s police switchboard and the customer services manager was named as “Tom Lloyd”: in fact, the chief constable. The headquarters was jammed with 2,500 angry callers in a day.

Cambridgeshire Constabulary said that a man from St Neots, Cambridgeshire, had been arrested on suspicion of causing a public nuisance. Asked by The Times if he had sent the hoax e-mails, Mr Francis-Macrae said that it was the first he knew of such a claim.

He cannot be prevented from sending out junk messages because a new British anti-spam law permits unsolicited e-mails for business purposes. Stephen Timms, the Minister for E-commerce, is being urged to tighten the rules.

Mr Francis-Macrae is a gifted computer enthusiast who began as a teenager swapping games equipment on the internet and has progressed to become a sophisticated young entrepreneur. He set up his first company while still an 18-year-old computer student at Cambridge Regional College.

Nicknamed “Weaselboy” on the internet, he lives in a brown-brick three-bedroom terraced cottage, built in 1885, with a stained-glass unicorn on the front door, in Bedford Street, St Neots. His father is a trained computer programmer.

Peter Francis-Macrae’s empire can be traced to “Unit 255” at 48 Regent Street, Cambridge. In fact, 48 Regent Street is a print shop known as Mail Boxes Etc, equipped with rows of lockers.

It collects letters for anonymous businesses and protects customers’ identities. “Unit 255” is the registered home of an array of ventures, most notably “premier-host.net”, which operates, improbably, from Jiangxi province in China.

The net host conveys messages promoting all manner of products. One spam says: “Join thousands of online users who discreetly, safely and conveniently order prescription medication for weight loss or diet pill medications, skin care, birth control, muscle relaxants, high level pain relief, anxiety, prescription sleeping aids, anti-depressant medications and more.”

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