He was arrested and questioned on Saturday, and his home and offices were searched. Mr Rimsevics was yesterday released on bail and his lawyer said he denied any wrongdoing. The latest allegations, first reported by the Associated Press, concern Norvik Banka JSC, which is controlled by Grigory Guselnikov, a Russian-born United Kingdom citizen.
The Bank of Latvia said it could not comment on the investigation, but said it had a "zero tolerance policy in respect of corruption and other illicit activities". Norvik's CEO, Oliver Bramwell, told The Associated Press: "The high-level official mentioned in our request for arbitration is Rimsevics".
Latvia's third-largest lender was left facing rapidly mounting problems Monday, after the U.S. Treasury accused it of money laundering and defying Western sanctions.
The latest allegations have put the government in a tight spot.
"I made a decision not to step down because I am not guilty", he said. "At the moment, none of Norvik Bank's representatives have submitted any evidence to any relevant authority".
"He says that he does not regulate the banking industry, that it is the financial regulator".
Latvian central bank governor Ilmars Rimsevics has been detained by the country's anti-corruption agency, the prime minister's office said in a statement on Sunday. The bank said its employees have never engaged in "any act of bribery regarding any official".
Gulselnikov has demanded 200 million euros to leave Latvia and give up his bank, Rimsevics claimed.
In his interviews with the AP, Guselnikov had also claimed that his bank had been asked by Rimsevics' associate to launder $100 million from Russian Federation.
"Now the regulator is trying to pretend there was no corruption". Then why would commercial banks try to attack him? "For 25 years Rimsevics has been directing things".
As governor, Rimsevics enjoys robust independence. Rimsevics will be replaced by the deputy governor, Zoja Razmusa, for the duration of his detention.
Dana Reizniece-Ozola, Latvia's finance minister, said Rimsevics "should resign from his post at least for the time of the investigation". "Of course we see that there is damage for reputation, first and foremost for Latvia and we expect that the national enforcement authorities will address the issue swiftly", he said.
Latvia's banking system has been under scrutiny in recent months, with several banks investigated, according to a BBC report.
The US Treasury sought sanctions against the bank last week, accusing it of allowing clients to conduct business with North Korea in violation of United Nations sanctions that were imposed in relation to its nuclear weapons program.