Drug-testing could also be used to help return children to their parents

In a letter to the Holyrood magazine, a member of the Association of Directors of Social Work said that Peter Peacock had shown interest in the proposal.

The association's Bernadette Docherty said testing would help make decisions about children who may be at risk.

A Scottish Executive spokesman said the discussions were an informal meeting.

The testing could also be used to help parents have their children returned to them if they could prove they were clear of drugs.

The measures could be carried out on a voluntary basis or the power could be given to Children's Hearings.

A number of recent cases involving children and drugs have come to light.

In March, a toddler died after drinking his parents' methadone and an 11-year-old girl collapsed in class after taking heroin in February.

Ms Docherty, director of social services at North Ayrshire Council, told BBC Radio's Good Morning Scotland that it was very difficult for social workers to establish grounds for removing children without drug testing.

The question is what level of harm are we prepared for children to face? Professor Neil McKeganey Director of the Centre for Drug Misuse Research

"Parents can say that they are drug-free and in the absence of objective evidence, it is difficult for us to prove to the contrary," she said.

"We all need to think about how we get the balance right between the rights of parents and the state's duty to intervene to safeguard children and their wellbeing."

Professor Neil McKeganey, director of Glasgow University's Centre for Drug Misuse Research, said that too much emphasis had been placed on looking after addicts rather than how they were looking after their children.

He added: "Children who are being brought up in the midst of serious illegal drug use are almost by definition being harmed.

"The question is what level of harm are we prepared for them to face?"