Thorough checks during the official count process revealed that a convicted prisoner managed to cast a vote when the Office of the Electoral Commission's mobile booth visited the Tanumalala Prison.

According to the law, convicted prisoners cannot vote; however, people in remand custody can do so. These are people who are kept in custody but have yet to be convicted.

Electoral Commissioner, Tuiafelolo John Stanley, said this was discovered this week during the beginning of the official count and that vote was considered informal (invalid) and not counted.

He said the prisoner could have been doing work outside in Tanumalala Prison when the mobile booth arrived.

"All these errors will always be discovered during the official counting," Tuiafelolo said.

More than 100 people who are currently in remand custody of the police at Tanumalala Prison last Friday when the mobile booth visited the facility.

Tuiafelolo said the reports that some voters used prisoners' names to vote are wrong.