A federal prison guard who became pregnant after secret trysts with double-cop killer Ronell Wilson was indicted yesterday by a grand jury.

Nancy Gonzalez, 29, of Huntington, LI, faces up to 15 years behind bars if convicted on the one count of having sex with an inmate.

Brooklyn federal prosecutors also announced yesterday that Wilson’s illicit relationship with Gonzalez suggests he continues to pose a danger to others, and therefore deserves execution for his crimes.

The feds plan to make this argument at a special trial in May, where Wilson will face the death penalty after being convicted of gunning down undercover NYPD detectives Rodney Andrews and James Nemorin on Staten Island in 2003.