Senior Scottish police officers called for an expanded DNA database which would hold profiles of anyone arrested for a crime - regardless of whether they are found guilty - following the conviction of two murderers this week based on DNA evidence.

Both Steve Wright, the "Suffolk Strangler" who murdered five prostitutes in Ipswich, and Mark Dixie, convicted yesterday of murdering teenage model Sally Anne Bowman in her driveway in a drug and drink-fuelled sex attack, were tracked down by police using DNA samples picked up while investigating unrelated crimes.

Unlike south of the border, where police retain DNA samples taken after arrest for relatively minor offences, Scottish police can only hold data on those convicted of a crime - although there are exceptions for registered sex offenders.

The Association of Chief Police Officers in Scotland (Acpos) last night said it wanted to mirror legislation passed in England and Wales in 2004 which allows for retaining DNA - a move that has enraged civil liberties campaigners and so far failed to win consent in the Scottish Parliament.

In a statement to The Herald, Acpos also warned that, although officers had the power to retain the DNA of registered sex offenders, they could only take samples up to a month after the date of conviction, a period it wants to extend.

"Acpos is in favour of mirroring any legislation passed in the UK Parliament allowing the taking and retention of DNA samples from persons arrested for an offence as well as for registered sex offenders whose profiles are not currently held," the statement said.

Acpos also called for DNA details of non-registered sex offenders to be held, arguing that this would be useful for comparison to scene-of-crime investigations and cold case reviews.

The move, reflecting Acpos policy on DNA profiling, was prompted by a call for a national DNA register to be introduced south of the border.

Detective Superintendent Stuart Cundy, the policeman who led the hunt for Sally Anne Bowman's killer, said having everyone's DNA on file would speed up arrests and cut down on further offending. The plea has the backing of Ms Bowman's mother, Linda, who has previously petitioned for the move.

Police were alerted to Wright as a suspect by a DNA sample taken and stored in 2003 for a petty theft he committed while working as a hotel barman.

Dixie was picked up almost immediately after a scuffle in a pub where he was working for 12 days during the World Cup which led to his DNA being sampled. It followed a nine-month investigation which had previously failed to identify the killer.

Mr Cundy said: "If there was a DNA register we would have known who killed Sally Anne that day."

In Scotland, DNA evidence has played a crucial role in a number of high-profile murder cases, some of which are still under way and cold cases including the World's End murder trial of Angus Sinclair, which eventually collapsed after a judge ruled that DNA evidence was not sufficient to proceed with the trial.

Among those who have been convicted are Daniel Jebb, who was jailed for 16 years after his DNA was found under the fingernails of Peggy Weir, a pensioner whom he stabbed to death in her Glasgow home. Police revealed later that more than 800 people had DNA samples taken during the investigation.

Civil liberty groups last night rejected the calls for further powers to take and record DNA.

Genewatch, the lobby group which has argued that widespread DNA profiling can criminalise ordinary members of the public and is subject to misuse and error, said it was not opposed to police using such samples in investigations. However, Helen Wallace, Genewatch's director, warned that taking DNA samples of everyone in the UK would cost "in excess of £1bn".

She said: "There is always the risk that it could be abused and that, instead of tracking criminals, you would have people using the database to track victims and relatives.

"As soon as you put good guys as well as bad guys on the database, you make it much more possible for it to be abused."