SEOUL, July 29 (Yonhap) -- Former Chief Justice Yang Sung-tae received a large amount of "special activity funds" amid allegations that he used trials as bargaining chips in the top court's dealings with the presidential office, a civic group said Sunday.

The People's Solidarity for Participatory Democracy (PSPD), released details about special funds that the Supreme Court doled out to top justices and ranking court officials from January 2015-May 2018.

A combined 965 million won (US$862,760) was spent in the name of special activity funds over the period. From 2015-2017, Yang received 23.1 percent of the funds, the group said.

In particular, the funds offered to Yang almost tripled to a monthly maximum of 13 million won in the July-December 2015 period when he allegedly had a solo meeting with former President Park Geun-hye.

An internal probe showed in June that the National Court Administration under the top court wrote a report in March 2015 on how to use high-profile cases in persuading senior presidential aides to then-President Park to support Yang's bid to establish a court of appeals.

"Yang met with Park in August 2015 for the establishment of the appeals court," the civic group said. "The special funds might have been used as lobby funds."

The top court plans to release more undisclosed documents over the scandal as early as Monday, according to court officials.

Source: Yonhap News Agency