Brazil's agriculture minister resigned Wednesday the president's office confirmed, as the minister became the latest in a string of top officials to step down amid corruption allegations.

"Over the last 30 days, I have faced a daily barrage of false accusations without any proof," Wagner Rossi wrote in a letter cited by Agencia Brasil.

Brazil's new president Dilma Rousseff, who took office at the start of the year, launched an anti-corruption drive in July, beginning in the ministries of transport and tourism.

"Everything is false, everything was contested. I answered each charge with supporting documents that the press just ignored," said Rossi.

Federal Police in Brazil this week opened an investigation into complaints of alleged corruption within the ministry, including accepting bribes, which Rossi allegedly had knowledge of.

In a statement, President Rousseff said she "deeply regretted" Rossi's departure, saying he had "made an important contribution to the government with quality projects that strengthened Brazil."

Rousseff added her disapproval that the minister had not been treated with a presumption of innocence in regards to the allegations.

Rossi is the fourth minister to depart the young administration, including Rousseff's chief of staff, Antonio Palocci, who resigned on June 7 over allegations of influence-peddling.

Palocci, a finance minister during the previous administration of Rousseff's popular predecessor Luiz Inacio Lula da Silva, reportedly amassed a huge fortune while serving in government and running a consulting firm.

Transport minister Alfredo Nascimento and 30 other officials resigned in July after accusations of corruption, and defense minister Nelson Jobim stepped down after making negative statements about the government.

The tourism ministry has also come under scrutiny, with the Federal Police issuing 38 arrest warrants earlier this month for officials and business leaders suspected of embezzling public funds.

Rousseff succeeded the charismatic and popular Lula, who left power with a record 80 percent approval rating after two consecutive terms that lasted from January 1, 2003 to December 31, 2010.

The two longtime allies will decide together on which one will seek the presidency in 2014, the country's communications chief said Wednesday.