The three escaped from Bangu prison by tying bed-sheets together and lowering themselves from a prison window to a rubbish dump.
Jean Carlos dos Santos, 37, is notorious for having had his lawyer killed after the latter failed to get two gang members released.
He had been in prison since 2017.
Jean Carlos dos Santos, also known as Jean do Morro do 18, controlled much of the drug trafficking in the Morro do 18 favela in Rio before his arrest.
A court also found him and another gang member guilty of the murder of his lawyer, Roberto Viegas Rodrigues, and of hiding his body.
An investigation revealed Rodrigues had been paid for getting two members of dos Santos’s gang freed from jail. When he failed to secure their release, he was shot dead.
The two other fugitives who broke out of prison in the early hours of Sunday have been named as Marcelo Sterque and Lucas da Conceição.
Police have released photos of the three fugitives, all of whom are considered highly dangerous.
One of them, Marcelo Sterque, had briefly broken out of the same jail once before. He walked out of the prison in 2015 to try to carry out a contract killing ordered by another inmate.
Sterque shot a woman 13 times before returning to his cell. An investigation at the time showed prison guards had been bribed to let him leave the prison and return unhindered.
But the victim survived and was able to identify Sterque as the man who had shot her.
On Sunday, prison officials said an investigation was under way to determine the exact circumstances of this latest escape.
Prison visits have meanwhile been suspended and 18 convicts with links to Jean Carlos dos Santos have been transferred to other jails.
Source : BBC