"He introduced the young woman to me as an acquaintance and did not give her name... I was very surprised and could not figure out if she was his girlfriend or just an acquaintance," Ernst Holzapfel said in a statement he read to journalists.
Mr Holzapfel said he met Ms Kampusch in mid-July outside a warehouse on the outskirts of Vienna that he rented out with Priklopil as an event location and where his press conference was held.
His story seems to confirm reports that Ms Kampusch sometimes left the house with her kidnapper. "I shook her hand, she said a friendly 'hello'. She made a friendly, happy impression," he said.
"At the time, I did not know it was Natascha Kampusch of course. I was only shown a (current) photo of her during the interrogation with the police and I recognised the young woman," Mr Holzapfel added.
Police say that there are several witnesses who say they had seen Priklopil and Kampusch outside his house or in the garden. "We are verifying that and hope to understand it in speaking with her," Lang told the APA agency.
Last Wednesday, while on the run just hours after Ms Kampusch had escaped, Priklopil contacted his friend of 20 years, Mr Holzapfel asking him, "please pick me up. It's an emergency, please come straight away."
Mr Holzapfel said he did not ask any questions and had no reason to doubt his friend’s story that he had fled a police check after driving drunk because he was afraid of having his license revoked.
"I knew that cars and his driver's license were 'holy' to him. Since I had known him for a long time, I did not doubt his explanation," he said, adding "he was very agitated, I had never seen him in such a state. But since he does not usually drink, I assumed it was a result of the alcohol."
Priklopil later committed suicide. Mr Holzapfel said that he only found out about the kidnapping after police approached him later and asked him to identify Priklopil from a photo, which he said "was horrible for me".
Never noticed a thing
Police say Mr Holzapfel, who is not considered a suspect. He described Priklopil as "friendly and helpful... thrifty but not stingy," somebody who "never wanted to stand in the foreground".
“I always thought that when you work well with someone for years, you also know him well... (but) the whole time, I never noticed a thing," Mr Holzapfel said, adding "I never would have thought he could be a kidnapper."
He said he had visited Priklopil's house and had helped with construction work on several occasions but that he notice nothing unusual.
The 40-year-old technician first met Priklopil during an apprenticeship with Siemens in the 1980s. He later worked with him renovating properties. His colleague Margit Weldenberger described him as "introverted, a typical technician" and said he cried when he first heard the news about Ms Kampusch.
Secret location
Ms Kampusch, now 18 years old, remains in a secret location surrounded by psychologists. After a four day break police resumed questioning the teenager about her abduction in 1998 and her subsequent detention in a basement cell of Priklopil’s house in Strasshof, 25 kilometres northeast of Vienna.
"Our first question is about the kidnapping, and especially to know if there was only one or several people involved," said police official, Gerhard Lang.
Up to now, Ms Kampusch who was taken as a 10 year old when she was on her way to school, has said Priklopil acted alone, but a witness, then 12 years old, has said he saw two people.
Dreams
Psychiatric expert, Reinhard Haller, said the kidnapper was probably dreaming of one day having a "normal" life with his victim, as she grew older, and was working to "slowly introduce her" in his public life.
When out, Ms Kampusch did not raise the alarm partly out of fear and also out of "gratitude" for these outings, Mr Haller said.