A North-East man has been accused of blackmailing a US supermarket chain with threats to put poisoned baby food on store shelves.

David Ian Dickinson, originally from Middlesbrough, was remanded in custody by Los Angeles Judge Jennifer Lum after a court determined he posed a danger to the community.

Dickinson, 43, is said to have been planning to return to the UK with his partner and child after collecting the £100,000 ransom money from store company Ralphs.

He was arrested by federal agents on Wednesday and charged with extortion and tampering with consumer products.

Unemployed Dickinson, who was living with his family in the Venice area of California on an expired visa, allegedly sent a package to a Ralphs corporate office in Compton containing four food products, including baby food and formula, with a letter labelled "blackmail demand".

A separate letter was sent several days later demanding £100,000. It threatened a wide range of tampered foods would be sent to stores if demands were not met.

Tests on the food products sent to the Ralphs office revealed a container of orange juice contained more than 50 per cent hydraulic fluid. Boric acid was found in a jar of horseradish and a container of Similac infant formula.

A jar of Gerber carrots also was found to contain glass shards.

US Attorney Debra Yang stressed no contaminated food products made their way into the food supply.

A preliminary hearing date has been set for May 20.

If convicted, Dickinson faces up to 25 years in prison.

Surveillance footage at a grocery store in Santa Monica showed a man on a bicycle who resembled the person seen on surveillance tape at the post office, where the package of contaminated food items was mailed.

Dickinson was later identified and a search of his home revealed clothing he allegedly wore when he posted the tainted food to the grocery store chain.

As part of what authorities described as an elaborate extortion plot, Dickinson allegedly demanded Ralphs place £100,000 in a bank account.

But he was arrested before he could access the account and as he was preparing to return to England.