A UK man has blamed his drug test results on Tesco's poppy seed bread.
The man's sister told local media she gave her brother four slices of his favourite poppy seed loaf to make sandwiches before his job interview.
The man then reportedly had to undergo a drug test as part of his job interview process and the test showed he had opium in his system.
The man says he had not consumed any medication or anything that could lead to that result.
"As he failed he didn't get the job no matter how much convincing he tried," his sister told Plymouth Live.
The family claims they later discovered the bread was the culprit.
His sister, who asked not to be identified, said she wanted to warn others of what could happen after four slices of poppy seed bread.
"Just a quick one for everyone to be aware of," she wrote on social media, according to the Daily Mirror.
"My brother went for a job interview today and had to do a drugs test he failed, with opium in his system.
"He doesn't take painkillers as he is scared of drugs and painkillers. Yesterday he came to mine and I had his favourite bread in he took four slices home with him, ate two yesterday and made a sandwich to take with him today as he was going to be at this interview all day.
"Poppy seeds caused him to fail his drugs test. As he failed he didn't get the job no matter how much convincing he tried," she added.
"So just a warning do not eat seeded bread with poppy seeds two to three days before a drugs test."
While poppy seeds are the seeds of the opium poppy plant, they do not contain any opiumin themselves. However, during the harvesting process, the seeds can absorb opium or become coated by it.
The UK supermarket chain says it has several policies in place to ensure they source bread seeds from low opiate varieties.
Mum loses newborn after failed drug test
This is not the first time poppy seeds are blamed for positive drug test results.
Last year, a US woman had her newborn baby take from her after she returned a positive drug test, only to be reunited when a later test cleared her - and bread has been pointed to as the culprit in that incident as well.
Rebecca Hernandez, of Huntsville, Alabama gave birth to her son at the Crestwood Medical Center and was tested for drugs after the birth.
When the test came back positive for opiates, staff at the facility called the Alabama Department of Human Resources, who came and removed the child and placed him with an aunt and uncle.
Hernandez then faced an agonising wait for a second test to be completed, which showed no opiates in her system.
Her doctor, Yashica Robinson, believes that poppy seed bread that Hernandez ate the day before she gave birth might be behind the initial result.
"Screening tests can have what we call false-positive results where other things can interfere," Robinson told WAFF news at the time.
"You can have a substance that a patient eats. Like in this case, poppy seeds can make them test positive for opioids."
Poppy seeds are actually derived from opium poppies and, while they can't get you high, they can sometimes contain traces, and morphine, and could show up in a sensitive drug test.