CALGARY -- Jann Arden is calling for a ban on prison drug-testing machines after her father and mother tested positive for cocaine and heroin.

The star told the Sun the incident occurred when members of her family visited her brother, Duray Richards, serving a life sentence in Bowden Institution for the Dec. 4, 1992 murder of a Creston, B.C. woman.

"Dad and I and mom were all swabbed," she said, speaking of a machine at the prison that takes swabs or swipes of visitors' personal articles and scans them for minute drug particles.

Her mom tested positive for cocaine and her dad for heroin.

"I tested positive for marijuana," Arden said.

The Ardens vehemently deny using any of those illegal drugs.

"I've never been convicted of a crime, but 60 seconds after they swab your stuff (the guards) look at you in a very accusatory way," Arden said.

Visits can be refused based on the tests, said Rita Wehrly, assistant warden of Bowden.

"The Ion scanner is in use in all federal institutions and the combined overall purpose ultimately is to reduce the supply of drugs coming into the institution," she said.

The tests have been criticized, mostly because the devices are so sensitive a person could test positive after brushing against something a drug user touched, such as money.

But the prison has no intention of retiring the machines.

About 70% of all federal inmates have a drug-dependency problem, Wehrly said.