Welsh start-up biotech company Cell Therapy, whose board of directors includes a former UK trade minister, has raised £691,000 through a crowd funding effort it claims is the largest ever by a drug development company anywhere in the world.

The funds will support a heart disease treatment pioneered by Martin Evans, winner of the 2007 Nobel Prize for Medicine for a breakthrough in stem cell research.

Cell Therapy said it has completed successful mid-stage trials for the treatment aimed at repairing muscle damage caused by heart attacks.

Collectively, the new investors will own just under 1% of the start-up. According to the newspaper Financial Times (FT), this implies a valuation of £75 million for the company and leaves Evans - who carries the title of Sir - and other founding investors with more control than if they had received venture capital.

Ajan Reginald, executive director and co-founder of Cell Therapy and a former executive of Swiss drugmaker Roche, told the newspaper the company turned down offers from venture capital funds in favor of private investments. Through the Crowdcube web platform, around 300 individuals pledged £37 to £108,000 in return for shares.

While Cell Therapy hopes the successful crowd funding will provide a new model for financing medical research, UK financial authorities are said to be concerned about the risk of exposing small investors to the high failure rates associated with biotech. The Financial Conduct Authority said it believed crowdfunders may be giving a "misleading or unrealistically optimistic impression" of investments.

According to the FT, this was the third crowdfunding in European healthcare in a week. Earlier, EyeBrain, a French medical diagnostics company, raised €1.3 million and Parkure, a Scottish start-up researching Parkinson's disease, collected £60,000.