An investigation has been launched into how unpaid workers bussed into London for the Diamond Jubilee celebrations were left stranded in the middle of the night.
The unpaid workers could get "restitution" as a result, the company responsible for providing the Government's Work Programme scheme in South West England said.
Prospects Group said it was launching the inquiry following allegations the jobseekers were forced to sleep in the cold under London Bridge before the Thames Pageant celebrations.
The firm said it was investigating the actions of employment charity Tomorrow's People, which was involved in organising the placements, and security firm Close Protection UK, which provided stewards at the Jubilee events.
A statement on the Prospects Group website said:
Prospects also said the investigation will focus on "the management of the project, supervision arrangements over the weekend, the working conditions, health and safety issues and the quality of the work experience provided to the apprentices involved".
According to reports, the jobseekers from South West England had to change into security gear in public and could not access a toilet for 24 hours.
After a 14-hour shift in the rain on Sunday - marshalling crowds who had turned up to watch the river pageant - they were then taken to a swamp-like campsite outside London, it is claimed.
But Molly Prince, managing director of Close Protection UK, said the situation had been "exaggerated."
Former deputy prime minister Lord Prescott condemned the "complete disregard" shown to the unpaid stewards.
The Labour peer, who has urged ministers to investigate, warned that the incident could set the tone for the treatment of workers during the Olympics.Ms Prince said there had been "logistical mistakes" but told Today:
She said the stewards had been left under London Bridge after their bus arrived there two hours earlier than scheduled.A Downing Street spokeswoman described the incident as an isolated "one-off" and said that Close Protection had apologised.The Number 10 spokeswoman said: