Brazil's President Jair Bolsonaro attends the flag-raising ceremony at his official residence in Brasilia, Brazil, July 22, 2020. (Photo by Lucio Tavora/Xinhua)

Brazil's President Jair Bolsonaro is suffering from an "intestinal obstruction," the government said on Wednesday, after the far-right leader was admitted to hospital due to persistent hiccups.

The 66-year-old far-right leader had been complaining publicly since last week about suffering from the hiccups following a July 3 surgery on a dental implant.

Bolsonaro was first taken to a military hospital in the capital Brasilia but was then flown in a Brazilian Air Force plane to Sao Paulo where he was admitted to the Vila Nova Star private hospital.

There he underwent clinical, laboratory and imaging tests and was being kept in the hospital for the time being, doctors said. 

"He is in good spirits and feels well," the presidency had said earlier in the day.

Bolsonaro was examined in Brasilia by Antonio Macedo, who has operated on the president several times since he was stabbed in the abdomen in 2018 while on the campaign trail. The hospital said he would "initially" be given a "conservative clinical treatment."

If it is confirmed he needs an operation, it would be the president's seventh surgery since he was stabbed by a former member of the Socialist and Freedom Party (PSOL), a group that broke away from the Workers' Party (PT) of former president Luiz Inacio Lula da Silva, who is eyeing a run against Bolsonaro next year.

Bolsonaro also contracted COVID-19 last year, although his symptoms were mild and he did not need hospital treatment.