PHILADELPHIA, PENNSYLVANIA - A couple from England who was visiting Canada and took a wrong turn into the United States - swerving to avoid an animal in the road - has been detained with their 3-month-old baby and shipped to the Berks Detention Centre in Leesport, Pennsylvania, according to their attorneys.

The baby boy has been subjected to frigid and filthy conditions, developing blotchy skin and what seems to be an eye infection, his mother wrote in a sworn statement. At one point the child was left naked and exposed for several hours in the cold jail, after all his clothes and blankets were taken for washing, she said.

The couple, David Connors, 30, and Eileen Connors, 24, say they were denied the right to contact their embassy.

"We will be traumatised for the rest of our lives by what the United States government has done to us," Connors wrote in her statement.

Attorney Bridget Cambria, of Aldea - The People's Justice Centre, filed a complaint on behalf of the family with the inspector general of the US Department of Homeland Security, which oversees the nation's immigration agencies.

"They had no idea they had crossed any boundary," Cambria said at a news conference Monday afternoon (Oct 14). "They had no idea they were even in the United States. They were just trying to get back to their hotel."

Cambria said it's likely the family will be formally deported, but no paperwork has been shared with them or their lawyers.

She described a bizarre scene of a family vacation turning into a nightmare. Other family members, including 2-year-old twins, also were taken into custody and moved to Berks, where they remain, Cambria said.

She did not know what kind of animal was in the road.

Officials with US Immigration and Customs Enforcement (ICE) said they were checking into the case and would respond to a request for comment as soon as possible. Federal Customs and Border Protection officials could not immediately respond.

Many federal workers were off Monday for the holiday.

The Berks County lock-up - long vilified by critics as a "baby jail" that should be closed - was designed to hold parents and their children who came into the United States without papers.

Formally known as the Berks County Residential Centre, the low-security lockup opened about 120km north-west of Philadelphia in 2001.

In her statement, Connors said that on Oct 3 her family was visiting Vancouver, Canada, and did not intend to enter the US. Her husband's cousin, Michael Connors, was driving close to the border, and when an animal suddenly appeared in the lane, he turned onto an unmarked road to avoid a collision.

In moments, multiple police cars and Border Patrol agents appeared.

David and Michael Connors were immediately arrested, she said, despite their protestations of innocence.

"You crossed an international border," the officer told them.

Eileen Connors wrote that she compiled the sworn account for her son, "because he is extremely vulnerable in detention."

The first night in custody, near the border with Canada, David was taken to a males-only cell, while she and the baby were placed in a women's cell. Both were given thin, metallic-looking emergency blankets, and left to sleep on the floor, she wrote.

She put the baby on top of her, to try to keep him warm, but he kept sliding off. "The memory of our little baby having to sleep on a dirty floor of a cell will haunt us forever," Eileen Connors wrote.

The next morning, the couple was told they would be released to a family member in the United States.

"It didn't matter that we told them all we wanted was to go home."

Later that day, immigration officials said there was a change in plans and they would not be released to a family member. That night, she wrote, immigration agents took the family from their cells, put them in a van and drove - "like an abduction or kidnapping."

They were taken to a new detention centre, where her husband was led from the van to what he later described as a freezing cell. She and the baby, Connors wrote, were taken to a hotel, a Red Roof Inn in Seattle (in the state of Washington). She had nowhere to boil water for her baby, relying on a microwave.

The next day, the family was taken to the Seattle airport.

"I thought, finally we're going home." Instead, she wrote, the family was flown across the United States to Pennsylvania. They arrived at the Berks centre on Oct 5.

Berks is one of three centres in the county that hold migrant families - the two others are in Texas - with a combined capacity of about 3,100 people.

All her child's clothes and blankets were taken for washing, even new items, she said, and the centre had no clothes small enough to fit.

She tried to wash the child as best she could while sitting on a sofa, because the baby bathtub that was offered was filthy, she wrote.

"When I ask how am I supposed to keep my baby warm in this horrible cold, all they tell me is to put a hat on him. ... They even took away one of his formula containers, which I had to beg for three days for them to return it to me."

The blankets and sheets she was given smelled "like a dead dog," Connors wrote, and she couldn't use them to wrap her boy "for fear they haven't been washed and my baby will become sick." The bathrooms are dirty and broken, she said.

At night, every 15 minutes, a staff person shines a flashlight into their room, awakening her and the baby, she said. She startles when the checks occur, because "I feel like someone is going to take my baby."

An ICE officer told her that if the couple wished, they could allow the baby to be separated from his parents and taken to another facility. She refused.

"We have been treated like criminals here, stripped of our rights, and lied to. It is not right," Connors wrote. "We have been traumatised. ... This would never happen in the United Kingdom to US citizens, or anyone else, because people there are treated with dignity."