Spending on DNA testing by Scotland's largest police force has risen by more than 2,500% in the last five years, according to a BBC investigation.
Strathclyde Police spent £65,000 on DNA testing five years ago
Strathclyde Police is now spending almost £1.7m a year on DNA tests - far more than any other force in Scotland.
Some lawyers have expressed concern at what they see as an increasing reliance on DNA by police.
But Strathclyde Police claimed DNA was helping to solve crimes more quickly and was saving money in the long term.
Across Scotland, forces have spent a total of £13m on DNA testing in the past five years.
At each force, spending has generally risen as the use of DNA to solve crimes becomes increasingly routine.
But by far the greatest change was in Strathclyde, where it jumped from £65,000 in 2003 to almost £1.7m last year.
But Det Supt William Prendergast said he believed it was money well spent.
"It's actually saving money - if we take the United Kingdom average for a murder inquiry, it can run between £1.5m to £2m per inquiry," he said.
"But because of the use of this investigative tool, called DNA science, these inquiries can be detected earlier."
However, some lawyers have raised concerns when DNA is used to make breakthroughs in older cases, where the evidence may have become contaminated over the years.
Most DNA samples taken after arrests in Scotland must be destroyed if the person is not charged or convicted.
Forces are only allowed to retain samples from those accused, but not convicted, of sexual or violent offences for up to three years.
A review of the procedures for keeping DNA samples from those accused of such offences was announced last September by Justice Secretary Kenny MacAskill.