Drugs firm PowderJect has received a takeover approach from an undisclosed bidder.

Previous merger talks with PowderJect, based at Oxford Science Park, collapsed last November after it rejected a number of tentative approaches from unnamed parties. They were believed to include offers from US firm Chiron and pharmaceutical giant GlaxoSmithKline.

The company said those discussions ended when it became apparent that the firm was unlikely to receive an offer in excess of a small premium on its share price.

Since then the shares have risen steadily. Yesterday the firm's share price climbed more than seven per cent.

In a statement PowderJect said: "The Directors of PowderJect confirm that an approach was recently made which may or may not lead to a formal offer.

"A further announcement will be made in due course."

Last year PowderJect became embroiled in controversy when it was awarded a £32m contract to supply the Government with a smallpox vaccine.

Chairman and chief executive Dr Paul Drayson had donated £50,000 to the Labour Party a few months earlier.

But a report from the National Audit Office cleared Dr Drayson of any link between his personal donation and the firm winning the contract.

The company has since benefited from an expansion in the market for flu vaccines.