A border collie that scientists say may be proof that dogs truly understand human language laps up media attention, but lets his owners do the talking.

Rico, the German dog who outshone all human competitors in a popular TV talent show, remembers the names of more than 200 objects and can figure out which item his master wants -- even if he has never heard the word before.

German researchers who have studied Rico for several years say he shows a skill, normal in young children, to form a rough meaning of a new word.

As they enthused at a news conference about him and the significance of his mental skills, he lay uninterested and nearly motionless under a table -- until a toy crocodile appeared.

Then he barked, awaited instructions and shook the relevant toy to photographers and reporters lying obediently at his feet.

"He just loves the cameras. He only has to hear a shutter opening to react," said Witold Krzeslowski, husband of Rico's owner Susanne Baus.

Rico developed his skills while laid low for nearly a year after a shoulder operation, with Baus trying to engage his mind and let his body rest.

"I discovered this talent and told my husband, who thought I was mad. At the start it was three to four objects, but it's risen to 200 or 250," she said. "I don't know what the limit might be, but we've now run out of space."

Rico won the German "Wetten Dass" (Wanna Bet?) TV program for weird talents five years ago and went on to be voted the best performer in the show's first 20 years.

But would-be collie owners be warned, Krzeslowski said.

"It can be hard to come home and get on with work. You first have to play 'fetch' with 20 objects. The only thing he accepts is when you are in bed. But he also gets up early in the morning."