A Mexican scientist accused of spying for Russia in Miami will be detained without bail for now, a federal judge decided Friday.

The temporary public defender for 35-year-old Hector Cabrera Fuentes said he agreed to remain in jail while his family works to hire a private lawyer.

“If your circumstances change, you could certainly request a bond at a later date,” U.S. Magistrate Judge Chris McAliley told Cabrera at a brief hearing. “We do expect that you will be able to obtain an attorney.”

Cabrera is charged with acting in the U.S. on behalf of a foreign government without notifying the U.S. attorney general and conspiracy to do so.

According to an FBI affidavit, a Russian government official tasked Cabrera with tracking down a vehicle owned by a U.S. government informant.

The FBI says Cabrera and his Mexican wife did this on Valentine's Day and were recorded by surveillance video at a Miami-area condominium complex. They attracted the notice of security by driving directly behind another car through a gate.

It's not clear exactly why the Russians wanted this done, but the affidavit says the informant had previously provided information about Russian intelligence operations and implications for U.S. national security.

Cabrera was detained Sunday while attempting to leave the U.S. at Miami International Airport and subsequently gave a statement to the FBI. Cabrera is listed as an associate professor at the medical school jointly run by Duke University and the National University of Singapore, and was working in Singapore.

Cabrera said in court Friday that his contract with that institution has been terminated but that he has savings to pay a private lawyer.

According to Cabrera's statement to the FBI, he has two wives — the Mexican one and a Russian one. The Russian woman and her two daughters were living in Germany but returned to Moscow last spring to attend to some administrative matters. Then, the Russian government wouldn't let them leave, the affidavit says.

That prompted Cabrera in May 2019 to visit his family in Moscow, where he was approached by a Russian official whom he had met previously at professional events and exchanges. Cabrera told the FBI he believed the official was an intelligence officer.

It's common for intelligence agents to insulate themselves by recruiting other people to carry out various tasks. Rarely does the recruit have full knowledge of the entire mission.

The Russian official, according to the affidavit, brought up Cabrera’s family situation in Russia and said, “We can help each other.”

Before Cabrera's Miami mission to photograph the informant's license plate, the FBI says the Russian official asked him to rent an apartment in the same complex as the informant but not in his real name. Cabrera paid an associate $20,000 to do so in late 2019, the FBI said.

It's not clear from the affidavit if anything was done with the apartment.

Cabrera, a microbiologist who has held several prestigious posts, is originally from El Espinal in the Mexican state of Oaxaca.

Another hearing is set for March 3.