The UK's justice system will take a "backward step" if the government closes its Forensic Science Service, experts have said.
They say the move would see the UK lose its position as the world leader in crime-scene investigations.
The Home Office said it was confident the move would not adversely affect the criminal justice system.
It has decided to break up the service, which makes an operating loss of £2m per month.
'Disbelief and dismay'
The letter has been signed by international scientists including the pioneer of DNA fingerprinting, Professor Sir Alec Jeffreys.
The scientists warn that the decision has has been met with "disbelief and dismay" around the world.
Prof Jeffreys said: "I would love to know a little bit more about the thinking, if indeed any thinking at all went into this bizarre decision, and whether that thinking involved any understanding whatsoever about the nature of forensic science and its importance in delivering justice."
International Society for Forensic Genetics president, Professor Niels Morling, who co-ordinated the letter, said there was global support to save the Forensic Science Service (FSS).
He said: "So many of us have benefited from the research, development and education offered by the FSS - a worldwide network of scientists is grateful to the FSS and to British society.
"Our plea to the British government is: 'Please consider what you will do next - ask where [you] will be in five or 10 years' time if this goes ahead?'
"Where will the research be? Who will do the development work? Who will look after the quality of forensic science in a competitive market? Closing the FSS is a backward step."
'Hasty and reckless'
The FSS has been involved in a number of high-profile cases, including those of Soham murderer Ian Huntley and Suffolk Strangler Steve Wright.
The Home Office says the FSS is expected to be wound up by March 2012, with the loss of about 1,600 jobs.
Crime reduction minister James Brokenshire said: "The Forensic Science Service is making significant and unsustainable operating losses and it is vital we take action to remedy this now.
"We believe in a competitive market, overseen by the Forensic Science Regulator to ensure quality standards are maintained. Research will continue to provide innovation in this area to help solve crimes."
He has said the Birmingham-based service could run out of money in January.
The FSS has two offices in Birmingham and sites in Chepstow, Chorley, London, Huntingdon and Wetherby.
Shadow home secretary Ed Balls said: "In what's becoming a consistent pattern of this Conservative-led government, ministers made this hasty and reckless decision without any consultation and little regard for the consequences.
"As this eminent group of scientists say, getting rid of the Forensic Science Service risks serious damage to the kind of pioneering research and innovation which has helped solve serious crimes."
http://www.bbc.co.uk/news/uk-12084761
