CAPE TOWN -- South African National Assembly Speaker Nosiviwe Mapisa-Nqakula resigned Wednesday amid investigations into corruption allegations against her.

"Today, the 3rd of April, I have submitted to the Acting Speaker of the National Assembly, Hon. Lechesa Tsenoli, my letter of resignation as both the Speaker of National Assembly and a Member of Parliament of the Republic of South Africa," Mapisa-Nqakula said in a statement. "The resignation is effective immediately."

"I have made this conscious decision in order to dedicate my time and focus to deal with the recently announced investigation against me by our country's law enforcement agencies," she said.

Mapisa-Nqakula, a 67-year-old veteran of the ruling African National Congress (ANC) party, has been facing corruption allegations that she solicited a cash bribe of about 2.3 million rands (about 120,000 U.S. dollars) from a former military contractor while she was defense minister between 2016 and 2019.

The speaker took "special leave" from her parliamentary position on March 21 after an early morning raid by a special investigations unit on her Johannesburg home.

Last week, she launched an urgent court bid to block her possible arrest, but a judge at the North Gauteng High Court in Pretoria dismissed her application Tuesday.

Citing court papers, local media reported Tuesday that Mapisa-Nqakula may face 12 corruption charges for allegedly soliciting bribes amounting to a total of 4.5 million rands during her tenure as the defense minister.

In her late Wednesday statement, Mapisa-Nqakula stressed that her resignation was "in no way an indication or admission of guilt regarding the allegations" being leveled against her.

"I believe that, at the right time, I will have the opportunity to thoroughly address these allegations as and when they have been formally brought against me in the appropriate forums, at which time I will clear my good name," she said. "I maintain my innocence and am determined to restore my good reputation."

"Given the public trust entrusted in me as the Speaker of our National Assembly and the need for me to protect the image of our organization, the African National Congress, I have an obligation ... to step down from my office," she added.

Mapisa-Nqakula also noted that she had informed the ANC leadership of her decision and she remains a "dedicated member" of the party.

In a statement issued later Wednesday, the ANC confirmed that it had officially received Mapisa-Nqakula's resignation letter.

"In her resignation, Comrade Nosiviwe Mapisa-Nqakula highlighted her intention to protect the reputation of our organization, the African National Congress, after dedicating more than 30 years of service," said the statement. "We value her commitment to maintaining the image of our organization, as it reflects our principles of organizational renewal that promote proactive responsibility-taking among members, rather than waiting for instructions to step aside."