Brazil's state-run oil firm Petroleo Brasileiro SA said on Wednesday it halted production at the Campos Basin's P-37 platform, which produces 30,000 barrels of oil a day, after an oil workers' union reported a leak.
Petrobras, as the company is known, said it had identified oil floating around the platform and halted production preventively.
Union FUP, whose workers are currently striking, said the leak started on Tuesday.
(Reporting by Gustavo Bonat)