"HE'S still got that gap in his teeth," a delighted Ken Thompson said last night after finally being reunited with his abducted six-year-old son Andrew.

"It was the first thing I looked for, and he's got that same smile and the same gap in his teeth as me.

"I thought, 'It's him, my boy, my Andrew'.

"He's got some sort of accent now, but he still speaks perfect English and he's got a strong little personality. It's my Andrew."

The former NSW deputy fire commissioner spent 40 minutes with Andrew in Amsterdam last night after a two-and-a-half year search following the boy's abduction by his mother, Melinda Stratton.

Mr Thompson, 57, cycled 6500km across Europe and generated a constant stream of publicity and internet postings about Andrew, and it was his internet presence that led somebody in Amsterdam to report Andrew's whereabouts to police.

A team of three Dutch psychologists carefully briefed the father and son to prepare them both for last night's reuinion - the moment Mr Thompson had been working towards for so long.

"I was nervous, I can tell you," he said.

"I've had so long to think about it, but boy did the butterflies start when I knew they were about to bring him in to meet me."

Mr Thompson was seated on a couch in a small room with lots of toys when the psychologists brought in Andrew.

"He was nervous too, but he looked at me and gave a little smile straight away.

"After all this time I didn't know how he would react and what his mother has told him about me. So it could have been pretty bad. But it was fantastic.

"He walked towards me and got close, then veered off and got some toys and asked me to play with him. We sat there playing a board game puzzle, and he slowly opened up a little as we played.

"I let him take control, and he really took the lead in how we spoke and what we spoke about."

Andrew asked no questions about his former life in Australia, or why he had not seen his father since he was three and a half.

"He's obviously trying to process everything and where I fit in and get used to me again, but we're on the way and it's going to be great," Mr Thompson said.

The meeting ran longer than the psychologists had planned, and neither father nor son wanted to part at the end.

"When it was time to go and to say goodbye, at first we shook hands then I thought what the hell so I gave him a hug and kissed him on the cheek.

"He didn't call me dad, but it was like we just resumed where we left off so long ago."

Andrew's mother fled from Australia in April 2008 in the middle of Family Court custody hearings after she had come to the opinion that Mr Thompson was abusing the boy.

Ms Stratton is in custody in Amsterdam awaiting extradition proceedings to Australia on criminal charges for allegedly taking Andrew out of the country in breach of a court order.

Mr Thompson is now waiting for Dutch childcare experts and psychologists to organise further meetings with Andrew.

He believes he may have to spend up to three months in Amsterdam before the boy is allowed to leave the country.

Read more about Ken Thompson finally being reunited with his lost son at The Australian.