A working group under the Organization for Economic Cooperation and Development(OECD) has conveyed its concerns to South Korea's justice ministry over the initiative to reduce the prosecution's investigative powers.

According to sources in legal circles, Drago Kos, chair of the OECD Working Group on Bribery, sent a letter on Friday saying that the proposal arbitrated by the assembly speaker could weaken the country's capacity to investigate crimes on corruption and bribery.

The official said if the mediated proposal gets passed, it appears that all legal provisions defining the prosecution's investigative rights will be eliminated, adding that Korea's indictment and probing powers against corruption and bribery must not be diminished.

Kos also expressed concern over efforts to pass the relevant bills before a May 10 deadline, and requested additional information regarding the case from the Seoul government.

Noting the urgency of the issue, he asked for a swift reply or an opportunity to engage in direct talks.

Meanwhile, Korean prosecutors practicing in the U.S. and other countries refuted the claim that prosecutors in developed countries do not have the right to conduct investigations before bringing charges.

The Korean Prosecutors Association said the argument voiced by supporters of the reform initiative in Korea is wrong, citing the ability by federal prosecutors in the U.S. to initiate investigations relating to suspected charges.