The government could be forced to cover riot risks at Yarl's Wood immigration detention centre because commercial insurers have no appetite to write the business.
The centre, which was wrecked by fire after asylum seekers rioted in February, was empty of detainees this week.
Security firm Group 4, which runs the centre for the Home Office, said operations were suspended because it could not buy the cover needed to keep it open.
Group 4 said insurer DJ Pye Syndicate 962 of Lloyd's cut its cover when the centre's policy expired at midnight on Sunday.
Active underwriter David Pye said the government would have to address the problem of cover: "The risk of riot in detention centres belongs with the government."
Broker Heath Lambert did not find any secondary insurers to back up Pye's cover, prompting fears other centres could be forced to close.
Group 4 will soon need to renew cover on a reception centre at Oakington, Cambridgeshire, and a detention centre in Oxford.
The government could end up footing at least part of the bill because Pye is claiming £43m compensation for the cost of the riot and fire damage through loss adjusters Capita McLaren from Bedfordshire Police under the Riot Damages Act .
Despite the centre's policy being held jointly by the Home Office along with Group 4, and builders Amey Construction, a successful claim against Bedfordshire Police Authority would ultimately come out of Home Office coffers.
Pye said: "All along we only wrote this risk on the basis that the riot Act would apply. The broker for the assured, Heath Lambert, was certainly aware of this