Korea's Ambassador to Australia Lee Jong-sup arrives to attend a meeting with other Korean ambassadors in Seoul, March 28. Yonhap

Ambassador to Australia Lee Jong-sup stepped down Friday, less than a month after he was named for the job, amid mounting criticism of his appointment and departure that came despite the fact that he was subject to an investigation.

Lee's resignation also came before Koreans go to the polls on April 10 to elect lawmakers. The controversy surrounding Lee has become a hot-button issue amid growing negative public sentiment and concerns even being raised from within the ruling party bloc.

The foreign ministry said it accepted Lee's resignation. The confirmation came hours after Lee's lawyer said the ambassador expressed his intent to step down to the foreign minister.

"As Ambassador Lee Jong-sup strongly expressed his intent to resign, the ministry reported it to the president, who has the appointment power, and decided to accept the resignation," the ministry said in a message to the media.

Lee has been under intense scrutiny since he was named the ambassador in Canberra early this month, after revelations that he had been banned from leaving the country over the investigation into allegations that he interfered in an internal military probe into a Marine's death last year.

Critics have accused Lee of running away from the investigation and leaving the country to take up the job shortly after the exit ban on him was lifted.

Lee has denied any wrongdoing.

Lee returned home on March 21, 11 days after he assumed the job, to attend a defense cooperation meeting of Korean ambassadors to six countries, including Australia. But questions arose that the meeting could have been organized to give Lee a pretext to come back home.

Lee plans to stay in Seoul to do all he can to "strongly respond to all procedures," according to Lee's lawyer, Kim Jae-hoon.

Offering his resignation, the ambassador asked the minister to make sure his resignation will be accepted, Kim said earlier.

The lawyer said that Lee repeatedly called for the anti-corruption investigation office to quickly summon him for questioning, but he still has not heard from the office.

Some have speculated that the presidential office ordered Lee to return home as the public sentiment was worsening ahead of the April elections.

Since his return home last week, Lee has met with foreign and defense ministers and taken part in a series of meetings with related ministries and government agencies that the ministry said took place to discuss defense cooperation with the six ambassadors.

Lee was reportedly absent from the ambassadors' meeting with the state trade insurance agency that he was supposed to attend earlier in the day.

Following Lee's resignation, the Australian Embassy in Seoul said the country expects to continue to work together with the succeeding ambassador.

"Australia greatly values its relationship with the Republic of Korea, and looks forward to working in close cooperation with the next ROK Ambassador to Australia across all areas of our comprehensive strategic partnership," the embassy said in response to a media query. (Yonhap)