The transport is being funded by the Bulgarian government.
Critics here now question who is responsible for European workers lured to Sweden to pick berries. The Swedish government has responded to calls for greater oversight.
The government now wants recruitment and personnel agencies based outside Sweden to register the number of workers with the Swedish Work Environment Authority.
"It will contribute to greater transparency on the labour market and increase the authorities' ability to safeguard working conditions," Employment Minister Hillevi Engström writes in an email to the TT news agency.
TT notes that not all workers are directly employed by the recruitment firms and have instead been lured here by vague promises of plentiful work in the Swedish forests.
There are at present no estimates of how many stranded workers there are in Sweden.