A cash-strapped county council has spent more than £15m since the start of April placing children in care homes in other parts of the country.
Northamptonshire County Council said there were currently 116 looked-after children and young people in care homes outside of the county.
While 155 children were being cared for in county placements, it added.
The cost since the start of this financial year of paying for the out-of-county placements has been £15.4m.
A spokesman for the authority, which last month agreed a £65m package of cuts, said: "It's very common for looked-after children to be placed outside of the county.
"In 2016-17, just 25% of children were cared for outside of the county, which is lower than other neighbouring authorities (31%) and well below the national average of 40%."
'Lack of places'
Labour county councillor Danielle Stone told the Local Democracy Reporter: "We have an army of social workers driving up and down motorways which reduces the amount of face to face time they have with the children.
"Because of the lack of places and capacity the market can call its own price and I think it is outrageous."
The county council, like most authorities, uses a number of private children's home providers to care for young people within its care.
The council's children's services department has been under the microscope in the past week following a damning verdict by watchdog Ofsted which, among several failings, revealed that 267 children did not have an allocated social worker.
A children's commissioner is expected to be in place soon to take over the running of the department.
In 2013 the Conservative-controlled county council's children's services was rated inadequate and in 2016 Ofsted inspectors upgraded the rating to "requires improvement".
But Ofsted says standards have "significantly declined" in the past two years and that the service has gone backwards.
Cabinet member for children Victoria Perry welcomed the appointment of a children's commissioner and the Ofsted report.
"What we must never lose sight of is that if this report means that already children in this county are safer then we must all welcome it and its findings. It is now our duty to fix what has clearly gone wrong," she said.