MAYWOOD, Ill. (AP) — Police in suburban Chicago are checking on the authenticity of Instagram videos that appear to show missing former NFL player Sergio Brown discussing the recent death of his mother, who died following an assault.

Brown, 35, is still considered a missing person, Maywood police spokesperson Carmen Rivera said in an email Tuesday, acknowledging police were aware of the videos and were investigating. Rivera did not immediately return messages Wednesday seeking an update.

In a video posted Monday to an Instagram page that appears to belong to Sergio Brown, a man resembling Brown calls reports about the death of his 73-year-old mother, Myrtle Brown, “fake news.”

“Fake news, fake news, fake news. It has to be the FBI,” the man says in the rambling, expletive-filled video, in which he says he thought his mother “was on vacation” in the Mexican state of Sinaloa.

In another video posted to his Instagram story Tuesday, the man references the film “Finding Nemo,” repeating the movie’s famous line, “Just keep swimming, just keep swimming,” the Chicago Tribune reported.

Myrtle Brown’s body was found Saturday near a creek behind her home in Maywood, about 12 miles (19 kilometers) west of Chicago. Relatives had told police they could not locate her or Sergio Brown.

The Cook County medical examiner’s office ruled Myrtle Brown’s death a homicide Sunday, saying she was injured during an assault.

Police said Sunday they were trying to find Sergio Brown and asked anyone with information on his whereabouts to contact them.

Brown’s brother, Nick Brown, memorialized their mother Sunday on social media, calling her “strong, caring, diligent, fancy, funny.” He asked anyone who knows his brother’s whereabouts to share information with police.

“I want him to know that I love you and please come home,” Nick Brown wrote.

Sergio Brown, who graduated from Proviso East High School in Maywood, played college football for Notre Dame before his time with the NFL. He played defensive back from 2010 through 2016 with the New England Patriots, Indianapolis Colts, Jacksonville Jaguars and Buffalo Bills.