Consumers have been urged to check that they do not have one of a batch of faulty pregnancy tests, amid fears that they could incorrectly show a positive result.

The makers of Clear & Simple digital pregnancy tests said there had been a “small number” of false positives, all related to a batch of the kits made in July 2017.

More than 58,000 affected kits were distributed in the UK, according to the manufacturer, Guangzhou Wondfo Biotech.

The Medicines and Healthcare Products Regulatory Agency (MHRA), which oversees medical devices and drugs in the UK, said that it had been alerted to the problem in early September.

The faulty kits all carry the same lot number, DM10220170710E, and have an expiry date of 9 January 2020. They have been available in the UK since last November.

The lot number can be found on the end of the box and is also printed on the sachet containing the testing stick.

People who have bought one of the affected batch have been advised to return it to the place of purchase and to seek an alternative test.

According to advice from the NHS, a positive test result is “almost certainly correct”, while “a negative result is less reliable”.

The MHRA urged people to check if they had one of the affected packs. Dr Duncan McPherson, the MHRA’s clinical director of medical devices, said: “If you have any questions about using digital pregnancy tests, please speak to your healthcare professional.”

McPherson said that anyone who had problems with the product, or with any other medical device, should report it via the MHRA’s Yellow Card scheme. This allows patients and healthcare professionals to tell the regulator about any issues with a drug or medical product used in the UK.

The MHRA said it had received details of the problem on 7 September. A spokesperson said: “When MHRA received the notification from the manufacturer we began our own internal processes to clarify the situation, including working out the magnitude of the issue and potential risks to public health.

“At MHRA we need to make sure our response to any report of device faults is proportionate and pragmatic.”

Around 15,000 tests had been quarantined or returned by the retailers, the MHRA added.

In a statement posted on its website on Thursday the UK distributor of the test, Healthpoint, said affected stocks had been removed from shops and were in its warehouse awaiting destruction.

“The majority of users of this lot have received accurate results when using the tests,” it said.

“We can assure you that all other Clear & Simple tests remain over 99% accurate as they always have been, and you can rely on results given.

“We are very sorry for any inconvenience and upset that this manufacturing fault may have caused, and we are working closely with the manufacturer to ensure the accuracy of future supplies.”

The test’s packaging claims that it is “over 99% accurate”, with a “clear digital reading” and results in five minutes.

In online parenting forums women had shared experiences of getting false positives from the test – in one post, one even speculated that there could be a faulty batch.