Common drugs taken by patients with high blood pressure and heart problems have been recalled amid fears they could cause cancer.

British pharmacists were today warned a change in how valsartan is manufactured has caused a dangerous impurity in several medications.

The Medicines and Healthcare products Regulatory Agency (MHRA) revealed the fault stems from a Chinese facility making the active substance.

The Government-run body, which polices the safety of medical products, warned the impurity is a proven carcinogenic in animals.

European health officials are working together to investigate the extent of the issue and any possible impact for patients.

A recall is also underway across the continent, following in-depth investigations into medicines containing valsartan. There is no evidence it has caused harm.

British pharmacists were today warned a change in how valsartan is manufactured has caused a dangerous impurity in several medications

Reports from media in Denmark suggest the impurities found in the medicine may stretch back five years. UK officials have yet to confirm that.

'There is no acute health threat to patients, but we know from trials with animals that it can cause cancer,' Doris Stenved, chief physician of the Danish Medicines Agency, told DR Nyheder.

'We don’t know if it has the same effect on humans, we just know it’s a substance that should not be in the medicine.'

Valsartan is an important prescription medicine used to treat high blood pressure and heart failure. It is also sometimes prescribed after a heart attack.

All batches of valsartan affected in the UK contain medicines made by Dexcel Pharma Ltd and Accord Healthcare, once known as Actavis Group.

The active substance - manufactured by Zhejiang Huahai Pharmaceuticals - is used in a number of medicines marketed in Europe.

The MHRA said the recall is simply a precaution - and warned patients should not simply stop taking the pills, if they are affected.

Dr Sam Atkinson, of the MHRA, said: 'People taking valsartan medication affected by this recall are advised to not stop taking their medication.'

Instead, he said they should 'speak to their doctor or healthcare professional who can advise on alternative treatment'.

Dr Atkinson added: 'We continue to undertake an urgent review of all these products that may pose a low risk to public health.

'We will communicate the outcome of our investigations and ensure that any other affected products are recalled.

'We strongly encourage anyone taking valsartan medicines to report any suspected side effects, to us via our Yellow Card Scheme.'

It comes after the MHRA today also issued a recall of scores of faulty tourniquets that may not stop patients from bleeding to death.

First responders and hikers were urged to check if they have a SAM XT Extremity Tourniquet, which can cost in the region of £40.

A problem in the sewing of the gadget may cause the seam holding the buckle to the belt to fail when used to stop blood flow, officials warned.