Rolf Harris has been accused of "deliberately lying" after he claimed he had not been in a town at the time he is accused of indecently assaulting a girl there - but a video proved he was.
Jurors in the trial of veteran entertainer have been shown footage of a TV game show starring the artist in Cambridge in the 1970s - despite the star telling them he had never been to the city until three or four years ago.
Southwark Crown Court was shown clips from an episode of Star Games, filmed in 1978, in which Harris competed.
Rolf Harris' trial was shown the video that proved he was in Cambridge in the late 1970s
Harris conceded it was him in the programme but denied deliberately lying, saying he had forgotten about it and did not actually know he was in Cambridge at the time.
Harris, 84, faces 12 counts of indecent assault against four alleged victims between 1968 and 1986. He denies them all.
One of his alleged victims, then aged 14, claims he groped her bottom outside the Cambridge event, describing him acting up for a crowd by barking at a dog before he grabbed her.
She believed the date to be around 1975.
The court previously heard there was no independent evidence to put Harris in Cambridge in that year.
He told the court he could not have committed the offence as he had not been to the city until a few years ago.
But on Monday, the court heard that new evidence had emerged in the form of video footage of Star Games, filmed at Jesus Green in Cambridge, in which Harris took part as a team captain and also competed in a swimming race.
The jury of six men and six women was shown the beginning of the hour-long show, introduced by Michael Aspel as being in Cambridge, and describing Harris as a team captain.
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Prosecutor Sasha Wass QC put to Harris that the event was the one that the alleged victim had described.
Wass said: "When you told the jury with such confidence last week on Tuesday that you had never been to Cambridge until four years ago, that was a deliberate lie, wasn't it?"
He replied: "No, it wasn't. I didn't find out that it was in Cambridge until I saw the video played back and then at the very opening the voiceover introduced it over what I remember was a helicopter shot of the field.
"That was the first time I had heard the word Cambridge."
He told jurors: "I had no idea. I don't think any of us knew."
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Harris told the court the performers had probably gone in a bus or coach to the green and he would not necessarily have known where he was.
He also said that what the alleged victim described as a marquee was not something he would have recognised as a marquee.
Harris said: "I was there but I didn't know it was Cambridge."
Rolf Harris denies 12 counts of indecent assault
Wass asked: "Are you saying that you entirely forgot that event?"
He said: "I did until I saw the video and then I remembered it all."
Pressed further, he said: "I'm doing hundreds of events during the year, going to Australia, Canada, New Zealand, South Africa.
"This was 36 years ago you're talking about, 1978, not '75 as you stated earlier."
Wass said: "I'm going to suggest that you are the one that has lied and that demonstrates it, and that there is no way you could have forgotten that event and you deliberately tried to mislead the jury when you told them that you had not been to Cambridge until four years ago."
Harris said: "I had forgotten that event until I saw that video."
He said he had not deliberately lied, but it was a "lapse of memory".