A sheep farmer said jars of baby food laced with metal were in Tesco stores in a blackmail plot, a court heard.
Nigel Wright is accused of sending letters and emails, signed “Guy Brush”, to the supermarket giant.
Mr Wright posed as a disgruntled dairy farmer who had been underpaid by Tesco and demanded 100 bitcoin, worth about £700,000 at the time, a jury at the Old Bailey was told.
He denies two counts of contaminating goods and four counts of blackmail.
Mr Wright, 45, from Market Rasen, Lincolnshire, tried to extort the cryptocurrency between May 2018 and February this year for revealing which stores he had planted the jars in, prosecutors said.
This sum demanded rose to 200 bitcoin, worth about £1.4 million in February, the court heard.
He claimed to be part of a group of dairy farmers calling themselves “Guy Brush and the Dairy Pirates” who believed they had been underpaid by Tesco.
Prosecutor Julian Christopher QC told the jury: “The defendant hoped to make himself rich by means of blackmail.”
Two customers had found slivers of metal in baby food jars as they fed their children in November and December 2019.
One jar was bought in Rochdale, the other in Lockerbie.
There is no evidence any other products were actually contaminated, the court was told.
Wright also claimed salmonella and chemicals had been injected into cans and threatened to continue poisoning Tesco products if payment was not made, Mr Christopher said.
‘Forced by travellers’
A draft of messages sent to Tesco was found on his laptop along with photos of food tins, jars of baby food and slivers of metal, the court heard
In one of the counts of blackmail, Wright allegedly threatened to kill a driver with whom he had had a road rage altercation unless he paid him bitcoin worth £150,000.
Mr Wright admits various elements of the campaign but claims he was forced to do so by travellers who had demanded he give them £1m and he was acting in fear of his life.
Mr Christopher told the jury it would have to determine whether the story of being threatened by travellers was true.
The trial continues.