A RESTRICTION on the right to silence in drug cases was agreed by deputies.

It was introduced as an amendment to the Drug Trafficking Bill by the Minister for Justice, Mrs Owen, and allows a court to draw "an inference" from the failure of an accused person to mention relevant facts during Garda investigations.

A conviction cannot, however, be based solely on such an inference.

The amendment was not debated as it was not reached before the Bill was passed under an agreed timetable.

The Bill allows for up to seven days detention by the Garda of suspected drug traffickers.

Opposition deputies demanded that protections for suspects be written into the Bill. Ms Liz O'Donnell, PD spokeswoman on justice, said interviews should be videotaped.

She moved an amendment which would provide access to a solicitor and medical treatment and declared that any garda who failed to observe regulations about the treatment of suspects in custody would be disciplined.

Mr Alan Shatter (FG, Dublin South) said most gardai behaved well but in states of tension abuses could arise. He supported the idea of seven day detention but it should be accompanied by safeguards.

Mr Tony Gregory (Ind, Dublin Central) said it was not the drug barons but the small dealers who were most likely to wind up in Garda custody.

It was important that safeguards be written into it.

The Minister said the protections were already there "This legislation for seven day detention was brought in so that we would have sufficiently penal powers available to deal with serious criminals."

It was confusing to have people calling for stricter laws one day and calling for the protection of civil liberties the next.

The PD amendment was defeated by 72 votes to 59. The Bill passed its remaining stages.