A frail 92-year-old woman was locked in a bank vault for 23 hours after staff forgot about her when she came to use her safety deposit box.

“The pensioner was left sealed in the high security chamber in total darkness and without food of water, when the BNP bank in Rennes, western France, closed for the weekend,” according to a Daily Mail report.

The paper said that the woman, named only as Germaine, was left alone by employees in the safety deposit room after she arrived at the bank at 11.30am on Saturday.

Her son finally alerted police that his mother was missing at 7.30am on Sunday after his repeated attempts to contact her had failed.

Police retraced her steps before tracking her down to the bank vault and releasing her at 10.30am on Sunday.

Rennes police commissioner Pascal Serrand was quoted as saying: “Her son said he remembered she was going to the shops, the cemetery and the bank on the morning she disappeared.

“She had no mobile phone to locate her, so we retraced her movements and concluded she must still be in the bank.

“A manager arrived and opened the vault and we found her inside.

“She was tired and thirsty but otherwise in good shape and very polite, and very pleased we had found her.”

An investigation had now been opened to establish if charges could be brought against bank employees for negligence, Commissioner Serrand said.

•Photo shows a high security chamber similar to the one where the old woman was sealed in total darkness and without food of water.