BOSTON – A couple who are members of a religious sect that rejects mainstream medicine on Tuesday appealed a ruling that would send them to jail for failing to turn over their newborn baby.

Rebecca and David Corneau were ordered held behind bars last week after they refused a juvenile court judge’s order to give the baby to state custody. In fact, the couple refuses even to acknowledge if they’ve had a child.

Massachusetts Appeals Court Justice Janis M. Berry heard arguments Tuesday and expected to rule on the appeal by Wednesday.

The Corneaus have a long history of conflicts with the courts and with the state over their children.

They are members of an Attleboro-based sect known as “The Body,” which came under scrutiny in 1999 with the disappearance of two children of sect members – including the Corneaus’ newborn baby boy.

David Corneau was one of eight members of the group jailed for refusing to answer questions from a grand jury investigating the missing boys. After spending 130 days behind bars and being promised immunity for himself, his wife and three other sect members, he led investigators to the two bodies buried in Baxter State Park in Maine.

His son was believed to have died shortly after birth and no one has been charged in his death. However, authorities believe the other boy – the 10-month-old son of another sect member – was starved to death. Three sect members have been charged with his murder.

The Corneaus’ four other children have been placed in state custody, with relatives who are not sect members. One daughter was born last year while Rebecca Corneau was being held for contempt of court for refusing a medical exam.

Children of other sect members also have been put in state custody.

Last week, Juvenile Judge Kenneth Nasif ordered the Corneaus to turn their new baby over to state officials after witnesses testified Rebecca Corneau appeared pregnant several months ago, but no longer appears pregnant now.

Defense attorney J.W. Carney, arguing before the Appeals Court on Tuesday, said there is still an open question whether there is a new child. The couple did not appear at the appeals court hearing.

He also said the Corneaus properly invoked their Fifth Amendment rights when they refused to answer questions for fear of self-incrimination. He said the couple has been persecuted repeatedly by the state for its religious beliefs.

Judge Berry brushed aside that argument.

“It is clear … that there are certain instances when a religious doctrine cannot stand in the face of harm to a human being,” she said. “I don’t think this is a case of religious persecution.”

Carney said the Corneaus fear criminal prosecution if they talk.

However, an attorney for the state Department of Social Services argued that the welfare of the child outweighs concerns of possible criminal prosecution. Attorney Virginia Peel also questioned the Corneaus’ refusal even to say if a baby had been born.

“If there is no child, there is no crime,” Peel said.

David Lewis, an attorney for the newborn, also said the potential risk to the child is the most significant concern.

“The only way to compel these parents to turn over this child is to incarcerate them,” he said.

Carney said if Berry upholds the juvenile court’s decision to send the Corneaus to jail, he will appeal again.