Jakki Balkwill, founder and owner of New World Security Solutions (NWSS), said the Pebble device she was developing would be capable of delivering slow-release medication, including anti-psychotic or anti-depressant drugs, and would include global positioning system (GPS) technology to enable police officers or doctors to locate people easily.

It will also detect changes in an offender's biochemical make-up, including hormone levels, which would alert authorities and allow them to react.

Chairman Sir Philip Hampton will tell shareholders at RBS's annual meeting at its Gogarburn headquarters, on the outskirts of the capital, that the investments will be made over the next three years.

However, Sir Philip is also expected to face discontent from shareholders over £607 million of staff bonuses awarded during a year when it lost £5.2 billion.

The investor has also called on the board of Rangers International Football Club to realign itself around chairman Malcolm Murray, declaring it bought shares on the strength of Mr Murray's City background and lifelong support of the club.

The institutional investor, speaking on condition of anonymity, declared it had never seen scandal engulf a company so soon after a flotation.

A senior executive at the investor said: "Within four months of the IPO [initial public offering], we have this scandal."

The British Retail Consortium (BRC), publishing the figures today, appears at pains to highlight the impact on sales of Easter having fallen earlier this year than last.

In spite of the reverse in sales, BRC director-general Helen Dickinson declared April had actually been a better month than March, especially for non-food sales.

She said: "On the surface, these are really poor figures but they're hiding another respectable month. The fact the boost from Easter didn't fall in April this year hit food sales in particular."