Prosecutors investigating allegations surrounding the so-called "Five Billion Won Club" linked to the Daejang-dong property development scandal have summoned former Supreme Court justice Kwon Soon-il for questioning.

The Seoul Central District Prosecutors' Office on Wednesday began interrogating Kwon as a suspect. This comes four months after his office was raided over related allegations.

Kwon is accused of receiving 150 million won, or around 109-thousand U.S. dollars, in legal advising fees from the developer in the Daejang-dong project between November 2020 and September 2021, without officially registering himself with the Korean Bar Association.

In connection to his appointment as adviser in the project, Kwon allegedly exercised a casting vote in a 2020 Supreme Court decision that reversed and remanded a lower court conviction of former main opposition Democratic Party(DP) leader Lee Jae-myung over public election law violation charges.

Kwon is one of six people suspected of being a member of the "Five Billion Won Club," each of whom were allegedly promised or paid five billion won from the project by Kim Man-bae, a key figure in the development scandal.