Brazil's President Michel Temer has been taken to hospital for an examination after experiencing "discomfort", one of his allies has said.
Carlos Marun is an aide to the embattled president.
He said on Wednesday he did not think the issue was serious but did not provide any more details.
Earlier this month, Mr Temer's office announced that he had been diagnosed with a partial coronary obstruction that would be treated with aspirin and a low-fat diet.
Local media has reported that the 77-year-old president's new admission to hospital is not related to his heart condition.
Mr Temer is facing a vote in the lower house of Congress on Wednesday that could see him suspended and put on trial on corruption charges.
Prosecutors allege he led a criminal organisation in which Brazil's political parties sold favours, votes and plum appointments to powerful businessmen.