Church leaders and the human rights group Black Mental Health UK have expressed their support for a debate on the discriminatory impact of the national DNA database on black and ethnic minority people that will come before Parliament on Friday.

The UK has the largest national DNA database in the world, with 4.5 million profiles expected to be held by the Government by 2010. Government figures suggest that 77 per cent of young black men will soon have their details held on the database.

The debate on the DNA database was called for by Liberal Democrat MP for Brent East Sarah Teather, who said, "The over-representation of black people on the Labour Government's database should horrify anyone who cares about justice and fair play."

Black Mental Health said there was a real danger that the DNA database "just reinforces the myth that black people are more likely to commit crime, and that is a very dangerous untruth".

Ms Teather said: "The truth is, if you are black, you are no more likely to commit crime and more likely to be a victim of crime."

Matilda MacAttram, director of Black Mental Health, said that black people tended to enter into mental health care through the police or criminal justice system.

"This means that countless people with healthcare needs are being criminalised in the process of seeking help. It is disturbing to know that those needing health care are on a criminal database," she said. "Wherever this is the case it is imperative that their details are removed as quickly as possible. This begs the question, what kind of a society criminalises those who need help?"

There are currently 500,000 people on the database with no current conviction, caution, formal warning or reprimand. Rev Paul Grey of the New Testament Church of God remains concerned over security issues after the Government admitted last November that the information of 25 million child benefit claimants and their parents had gone missing in the post.

The "injustices of bad science" could lead to the DNA information of being abused in the future, he said.

"The public have no way of knowing how secure this information is that they are taking. If someone steals your DNA what the implications?" he said. "Loosing child benefit details is one thing, but a person's DNA is part of who they are. This is another hostile move against the freedom and civil liberty that should be protected."

Pastor Desmond Hall, chair of Christians Together in Brent, added, "The database most unwelcome and is bringing division rather than healing within our communities, as it is our young people being stopped by the police, often for no justifiable reason.

"We have no confidence in the Government controlling this, in light of the recent data losses we have seen, and this information in the wrong hands could be catastrophic."