Growing numbers of fake medicines linked to coronavirus are on sale in developing countries, the World Health Organization (WHO) has warned.

These drugs could have serious side effects, WHO warns. One expert warned of a parallel pandemic, of substandard and falsified products.

With the world's two largest producers of medical supplies - China and India - in lockdown, demand now outstrips the supply and the circulation of dangerous counterfeit drugs is soaring, BBC reports.

Wrong or no active agreement

According to the WHO, the broader falsified medicines trade, which includes medicines which may be contaminated, contain the wrong or no active ingredient, or may be out-of-date. It is worth more than $30bn in low and middle-income countries.

In the best case scenario the fake medicines probably won't treat the disease for which they were intended, said Pernette Bourdillion Esteve, from the WHO team dealing with falsified medical products.

But worst-case scenario they'll actively cause harm, because they might be contaminated with something toxic."

People anxiously stockpile basic medicines

With an increasing number of countries going into lockdown, it's not only the reduction in production that's problematic, it's also the increase in demand, as people around the world anxiously stockpile basic medicines. It's this unstable combination of reduced supply and increased demand that has led the WHO to warn of a dangerous spike in the production and sales of fake drugs.

When the supply does not meet the demand," said Esteve, from the WHO, "it creates an environment where poorer quality or fake medicines will try to meet that demand."