In the latest scandal to hit the country's notoriously corrupt prison system, Vanny Rossyane, 22, said she had visited drugs kingpin Freddy Budiman three times a week at the Cipinang penitentiary complex in the capital, Jakarta.
Rossyane's account has led to a flurry of salacious media reports and comments on Twitter, some denigrating the couple and others calling for the warden to be sacked.
A spokesman for the correctional facilities department at the justice ministry said the prison warden was being questioned.
The Cipinang penitentiary, where high-profile corruption convicts and wealthy drug dealers are locked up, has been long criticised for giving special favours to those who can pay.
The jail has been caught giving some prisoners large private rooms and allowing them to bring in maids, furniture, air conditioners and televisions.