A woman put people's lives at risk by unwrapping Lindt chocolates and swapping them for marbles and rubber balls before returning them to stores to be sold to unsuspecting customers.

Wendy Purser, 55, admitted contaminating or interfering with boxes of Lindt Lindor chocolates between March 10 and May 16 last year.

She had bought the boxes from Waitrose in Billericay's High Street, Asda in Eastgate, Basildon, Asda Living in Lakeside and Wilko in Brentwood.

Basildon Crown Court heard on Thursday that she had taken out individually wrapped truffles, swapped them with small objects about the same size, before wrapping them back in the paper and placing them inside the boxes.

She concealed her crime by opening the boxes from the bottom and resealing them, before handing them back to stores claiming she didn't want them anymore, the court heard.

Frank Ferguson, deputy chief crown prosecutor for the CPS East of England, said Purser, of Little Russets, Hutton, put members of the public at serious risk of choking.

He said: “Fortunately, Wendy Purser’s actions in contaminating boxes of Lindt Lindor chocolates in stores in South East Essex were quickly discovered and no harm came to anyone.

“But what she did by contaminating these chocolates put members of the public, and especially children, at real and serious risk of choking.

“Her method of contamination was to open the boxes from underneath, take out the individually wrapped truffles, throw away the truffle and substitute small objects such as rubber balls, marbles, conkers or balls of wool.

"She would then wrap these items in the paper from the truffles and put back them in the box, which she then sealed.

“Having previously bought the boxes of chocolates, Mrs Purser would then return them to the store as unopened for a refund and they would be put back on the shelves to be bought by unsuspecting members of the public."

Mr Ferguson said Purser had no real motive or reason for risking people's lives in this way.

He said: “When she was arrested, it was not clear what Mrs Purser’s motives were for doing this. She and her family do not have any connection to Lindt, or any apparent reason for a grievance against the firm.

"No blackmail demands were made either to Lindt or to the stores where she returned the chocolates.

“Contaminating food in this way is a serious matter and the charge we selected after considering the evidence against Mrs Purser reflects this as it carries a maximum sentence of 10 years’ imprisonment.”

She was handed a 12-month prison sentence, suspended for two years.

An Essex Police spokesman said: "An investigation was launched by Essex Police in April 2015 following contact from The Food Standards Agency. "We recovered nine 200g boxes of chocolates which had been tampered with.

"The chocolates in the boxes had been replaced with wooden, glass, plastic or wool balls."