Lindsay Durdle died on May 31 aged 37. She had been first diagnosed with breast cancer about a year and a half earlier. The disease had later spread to her lungs and brain. PayPal was informed of Mrs Durdle's death three weeks ago by her husband Howard Durdle. He provided the online payments service with copies of her death certificate, her will and his ID, as requested.

Then he got a letter from Paypal addressed to his dead wife sent to his home in Bucklebury, West Berkshire.

It was headlined: "Important: You should read this notice carefully." It said that she owed the company about £3,200 pounds and went on to say: "You are in breach of condition 15.4(c) of your agreement with PayPal Credit as we have received notice that you are deceased... this breach is not capable of remedy."

The firm has since acknowledged that the letter was "insensitive", apologised to her widower, and begun an inquiry into how it came to be sent. According to a PayPal staff member, there were three possible explanations for how the letter was sent: a bug, a bad letter template, or human error.

PayPal is continuing to work with Durdle and has written off the debt in the meantime.