The NYPD is investigating a letter sent to the mother of the suspect accused of killing Queens jogger Karina Vetrano that was reportedly covered in blood and feces, police said.

The 75th Precinct was tasked with investigating the letter after Veta Lewis filed an aggravated harassment complaint on Feb. 23, 2017, police said.

The letter was streaked with blood and feces, and demanded an apology from Lewis, the New York Daily News reported.

A spokesman for the Lewis family told the Daily News the letter also urged Lewis to return money the family had raised on a GoFundMe page which has since been taken down due to violating the website's policies on fundraising for criminal defenses.

Lewis’ 20-year-old son, Chanel, stands accused of attacking and strangling Vetrano while she jogged along a trail inside Spring Creek Park in Howard Beach, Queens on Aug. 2, 2016. Hours after she had left for the run, she was found lying face down in a marshy area off the trial. Lewis was charged with second-degree murder on Feb. 7, 2017.

In the intervening months, the case was kept in the spotlight by Vetrano's parents, who held press conferences and spoke with reporters frequently.

Police have said Lewis was finally linked to the case after investigators created a DNA profile based on a 911 call about a suspicious person in the area of the park that was reported in May — months before the attack. Chief of Detectives Robert Boyce said investigators happened on the call during a “deep dive” into the case.

Lewis was later linked to Vetrano's murder by DNA evidence, police said.

On Tuesday, Lewis' family and friends staged a rally outside the Queens courthouse where he appeared for a brief hearing.

The group had questioned the reliability of the NYPD and complained of problems raising money for legal support. 

“We want to make sure all of the facts regarding this case are facts and not fabricated,” local clergyman, the Rev. Kevin McCall, told reporters. “We are calling for justice to be rendered and due process to be served with this family.”

Lewis' parents did not speak during the rally.

With Vincent Barone and Newsday