The 19-year-old Florida student accused killing a couple at their home and eating the man's face told police "Help me, I ate something bad" before replying it was "humans" and spitting out a piece of flesh while in hospital, according to reports.

Austin Harrouff is also said to have shouted "kill me... shoot me now, I deserve to die" at officers while they were arresting him at the scene of the incident at Jupiter near West Palm Beach.

Harrouff has been charged with the second-degree murders of John Stevens, 59, and his 53-year-old wife Michelle Mishcon outside their home on 15 August, as well as attacking the neighbour Jeff Fisher as he came to their aid. He is also suspected of biting the face and body of Stevens while making animal-like "guttural" noises.

According to documents by Martin County sheriff's deputies, obtained by the Palm Beach Post, Harrouff said "Help me, I ate something bad," while he was hospitalised at St Mary's Medical Center. When a sergeant asked him what he ate, the 19-year-old replied "humans".

According to the report, one arresting officer pointed his gun at Harrouff and urged him to get off Stevens during the attack. A second officer arrived to Taser the suspect, but he still did not let go.

Eventually the deputy described how he "kicked Harrouff in the head several times" and he briefly got off Stevens, but soon jumped back on to continue chewing the victim's face.

Police had previously described how the suspect was "abnormally strong" during arrest, with officers also deploying a police dog to help subdue him.

Martin County Sheriff William Snyder told WPTV that what Harrouff told officers at the scene of the killings is "all he has said to us, on the record or off the record".

Harrouff spent almost two months in Palm Beach County hospital in a serious condition following his arrest. Officers believe he may have ingested some sort of lawn chemicals found in the couple's garage, which may have affected his behaviour.

Tests have revealed the 19-year-old was not on any street drugs at the time of his arrest and was having a meal with his family less than an hour before the attack. His family said he stormed out of the restaurant about four miles from the victims' house after having a heated exchange of words with his father.