A "dirty, long, filthy fingernail" was almost swallowed by a disgusted diner at Watford Jimmy’s World Grill in a mouthful of made-to-order Indian pancake.

Antoinette Miller, 42, from Cassiobury, was eating a specially prepared dosa pancake when she felt something crunch in her mouth.

The church volunteer was "disgusted and appalled" and left retching into her food at the table when she pulled out the offending fingernail.

Managers at Jimmy's, in High Street, apologised for Ms Miller's experience but said the nail had come from another guest helping herself to the buffet.

Ms Miller said: "I started eating, it crunched and I felt something inside my mouth. It was a fingernail, a really dirty, long, filthy fingernail.

"It was disgusting. I felt sick.

"I called the manager out and told him what happened, he was embarrassed and said I didn’t have to pay for my meal.

"But I’m so appalled. I was retching at the table."

Ms Miller had taken her parents to the restaurant to celebrate her father’s return from Sri Lanka.

Ms Miller said: "I had taken my parents to lunch, the day after my dad had flown in from Sri Lanka - they were equally appalled. I have been there before and nothing like this had happened, I won’t be going back."

Ansh, manager at the Watford Jimmy’s, said the incident had been investigated and none of his staff were responsible.

He said the most likely explanation is that the nail came from another customer.

He said: "The lady was very upset, we did not give her the bill and explained to her what might have happened - that the nail came off another guest helping herself to the food.

"I would be outraged if it happened to me. We apologised, paid for the meal and invited her back for another meal."

Ansh said Jimmy’s was very proud of its food safety record and incidents like this are exceptionally rare.

He continued: "We have the highest standards of food safety, our chefs are trained and we have food processes for each dish that are checked without notice by environment and food safety officers.

"We are very proud of that and we need to make sure all of our guests are safe and the food fit for consumption.

"We investigated this incident and we cannot find a reason for it. It is a buffet and contamination can take place. We looked at the cameras and we could not see the incident, we think what must have happened is that the nail came from a female guest helping herself to the food.

"The pancake batter is prepared by a machine and is not touched by human hands, and our female members of staff do not have long nails."