James McKeever, 64, got a four-year jail term for eight sexual offences against a girl between 1981 to 1988.
The victim was aged between seven and 14 at the time of the abuse.
As well as the jail term, McKeever was also placed on the Sex Offenders Register for an indefinite period.
The former deputy mayor of Derry City and Strabane District Council was suspended from the SDLP when the charges first came to light.
He was then expelled from the party following the guilty verdict, and the party asked him to relinquish his council seat.
As of Monday, James McKeever was still listed as a representative for the Faughan district electoral area on the council’s website.
Following McKeever’s sentencing, a spokesperson for the council pointed to Section Four of the Local Government Act (Northern Ireland) 1972.
The legislation states that a person will be disqualified from acting as a councillor if they have been sentenced to a period of imprisonment for three months or more without the option of a fine.
The council has advised the Electoral Office of the conviction, and that it is now taking advice on the matter.
Chief Electoral Officer Virginia McVea said she had not yet been informed of a casual vacancy.
“At this point I am given to understand that the seat, if declared vacant, would return to the SDLP,” she said.
An SDLP spokesperson said the party had suspended McKeever as soon as charges were brought and formally expelled him from membership following his conviction.
“Given the seriousness of these offences, we called for Mr McKeever to resign his seat on Derry City and Strabane District Council immediately,” they said.
“It is a matter of regret that he chose not to.
“The SDLP will shortly begin a process to appoint a new councillor to represent the Faughan DEA upon receipt of confirmation from the Electoral Office of the vacancy.”Tags: