A Birmingham woman was treated to a nasty surprise when she bit into a Mars Bar, only to find a light bulb about the size of the tip of a finger.

“There was no bleeding, my teeth are OK but I’m absolutely disgusted. I could have eaten it,” Michelle Harley told the Birmingham Mail. “The purpose of the chocolate bar was to give it to my son. I will never buy a Mars Bar again,” she continued.

A spokesperson for Masterfoods, the UK unit of Mars, told just-food that Harley contacted the company directly but that the investigation has been turned over to the UK’s Trading Standards authority.

“The whole thing is being investigated by Trading Standards and we will assist them in their investigation in any way possible,” he said. “As an organisation, we seek to make sure that our products arrive at our consumers in a first-class condition.”

As yet, there is no indication of how the light bulb made its way into the chocolate bar, Masterfoods said.