The former Barcelona icon has been behind bars since being arrested last week for entering a Paraguay with a false passport.

The World Cup winner, 39, is being kept at a maximum security facility outside the capital Asuncion along with his brother Roberto.

Ronaldinho ARRESTED as judge rejects prosecutor's recommendation to release Brazilian superstar over fake passport 

They had requested to be moved to house arrest – offering a  US$770,000 property as a guarantee – but saw that bid rejected as a judge ruled Ronaldinho’s freedom “could lead to an obstruction (of justice) or an escape,”Reuters reported. 

"His presence in the country is necessary," said judge Gustavo Amarilla.

Meanwhile, prosecutor Marcelo Pecchi told reporters that the pair posed a flight risk.

"The investigation is only beginning, we are looking into other conducts that may be related," he said. 

"If these people leave right now they will not be able to be brought to face trial because Brazil does not extradite its own citizens."

Ronaldinho – who scooped the Ballon d’Or prize for the world's best player in 2005 – could face up to six months in prison while the claims against him are investigated.

He had arrived in Paraguay in the middle of last week to conduct charity work and promote his book, Genius of Life, although was subsequently detained after suspicions he had entered with false documents.

A prison warden subsequently told Reuters that the football icon was “doing well” as pictures emerged of him in jail, although it’s as yet unclear how Ronaldinho took the rejection of his latest appeal.