A leaked letter from a consultant has revealed how he advised surgeons and colleagues to "downplay" the benefits of new digital hearing aids.

Jeremy Tweed from Dorset County Hospital in Dorchester said he could not afford to give every patient such an aid even though they were better than traditional analogue aids.

The Royal National Institute for the Deaf (RNID) has deplored patients being misled.

Chief executive James Strachan said: "There is no excuse for falsely playing down the benefits of digital hearing aids - but Mr Tweed should never have been put in this position in the first place."

The letter was written by Mr Tweed, the head of audiology and hearing therapy at the hospital, in August.

'Shoestring' budget

In it he said candidates sent for assessment for a hearing aid should not be told what type they might get.

"It is also very helpful to us if you can downplay the benefits of digital versus standard NHS hearing aids," he wrote.

But the RNID said digital aids were preferred by most patients because of their improved sound quality.

Mr Strachan said: "Mr Tweed is trying to run an audiology department on a shoestring and modern hearing aids cannot be provided while the government is starving them of cash."

But Mr Tweed's comments have been described as "not appropriate" by a spokesman for the West Dorset General Hospitals NHS Trust.

A spokesman said the department wanted to advise patients rather than allow "preconceived ideas" about hearing aids to influence decisions.

The trust said it was now spending �250,000 a year on hearing aids - up by 50%.