The search for Etan Patz -- a 6-year-old boy who disappeared more than three decades ago-- in a SoHo basement ended with no human remains or blood being found.

The NYPD and the FBI have been searching the basement on Prince St. in Manhattan since Thursday. They were digging through cement and bringing in cadaver dogs in hopes of finding the remains of the boy who disappeared in 1979.

After an initial search, police discovered a possible blood stain. However, after an analysis, they concluded it contained no trace of bodily fluids. The search for human remains in the basement turned up empty. Strands of hair were also discovered, but they do not appear to match those of Patz, reported the New York Post.

No obvious human remains were found, but it's still a missing person case, said Paul Browne, spokesman for the New York Police Department, reported the Associated Press.

Steel containers full of rubble and sand were hauled away from the scene on Monday, however, in case investigators need to take another look at the potential evidence. They will be kept in a landfill in Staten Island.

After closing the block, while investigators conducted the search, the area was reopened on Monday.

The FBI has concluded the on-site portion of the search, FBI spokesman J. Peter Donald said, reported the AP. The street and local businesses will be re-opened.

Still, police and FBI officials sent the piece of wall that they originally believed contained traces of blood and the strands of hair for further testing at lab in Quantico, Va.

On May 25, 1979, Patz left his building on Prince St. and was never seen again. For over 30 years, investigators have come up short in finding out what happened to the 6-year-old.  Patz lived only 100 yards from the basement on Prince St. and would have passed by it often as he walked to the bus stop, where was he headed the day he disappeared, reported CNN.

In 1979, a handyman, Othniel Miller, who is now 75-years-old, used the basement. The Post reported in the initial search of the boy, police officers questioned Miller after noticing fresh concrete on the floor. However, they never dug it up.

Mr. Miller decries these efforts to sully his good reputation and destroy his family,'' said Michael Farkas, Miller's lawyer. He has absolutely no responsibility for the terrible tragedy that befell young Etan Patz, and he grieves for Etan's fate, as all New Yorkers have for decades.

Police began investigating the basement about a month ago when a cadaver dog reacted to the floor, reported CNN. However, Miller has not been charged with any crime and his lawyer denies his client had any involvement in Patz's disappearance.

Mr. Miller has been cooperating with this investigation for over 30 years, Farkas said on Friday, reported CNN. He has continued to cooperate on multiple occasions. And I am going to assist him in cooperating to the fullest extent possible.

Etan's parents, Stan and Julie Patz still live in the same apartment where their son lived. They also maintained their same phone number in case their son ever reached out to them.

In 2001, Etan was declared legally dead so they can sue the man they believed was responsible for their son's death, Jose Ramos. In 2004, a civil judge declared him responsible for Etan's death. Ramos is currently in prison in Pennsylvania for molesting two children and has denied having any involvement in the disappearance of the boy, reported the AP.