An international forensic expert gave evidence in the High Court at Wellington yesterday about how tests were undertaken on the marks, which found brain matter present.
The Crown earlier said DNA likely to be from Lundy's wife Christine, 38, was found on the polo shirt.
Lundy has denied killing her and their 7-year-old daughter Amber in their Palmerston North home on August 30, 2000.
Forensic scientist Laetitia Sijen from the Netherlands Forensic Institute will continue to be questioned today about tests the company performed on the shirt.
Yesterday, the jury was given complex evidence about the testing processes.
Dr Sijen said there was "very little cell material present" so their testing processes needed to be developed.
The test results showed the mark on Lundy's sleeve was more probably than not central nervous system (CNS) tissue, Dr Sijen said.
"From the results we infer that human CNS tissue was present."
The tests were performed in front of an expert from Lundy's defence team.
No CNS tissue was observed on the mark on Lundy's pocket, but that did not mean it was not present, Dr Sijen said.
Defence lawyer David Hislop questioned the institute's error rate and pointed to a newspaper article that showed the institute had 1700 incidents in the past 14 years.
Dr Sijen said the number of errors compared with the number of tests run was "relatively low".
The trial in front of Justice Simon France continues.
By Rebecca Quilliam of NZME. News Service
