TOKYO (AFP) - England's training session ahead of their upcoming Rugby World Cup semi-final was covertly filmed by an unknown sleuth, coach Eddie Jones said on Tuesday (Oct 22).

Most leading nations including England keep their practice secret, with strict limits on who is allowed into the ground to ensure opponents cannot spy on them ahead of a game.

"There was definitely someone in the apartment block filming but it might have been a Japanese fan," said Jones, whose men face reigning champions New Zealand in Yokohama on Saturday.

Access to training sessions is typically only given to accredited journalists, photographers and broadcast cameras.

But the Australian appeared to shrug off the suspected infringement, saying that his team "don't care" and that it "doesn't change anything" due to the modern media ecosystem.

"You can watch everyone's training on YouTube. There's no value in doing that sort of thing, absolutely zero," Jones said.

The coach even admitted that he "used to do it" himself but has not done so since 2001.

Jones, who was in charge of his native Wallabies when they lost the 2003 World Cup final to England, was appointed to the England job shortly after the team's miserable first-round exit on home soil in 2015.

They now face an All Blacks side bidding to lift the Webb Ellis Cup for the third time in a row, and the fourth in New Zealand's history.

The title holders were hugely impressive in a 46-14 quarter-final thrashing of Ireland, while England reached the last four with an almost-as-emphatic 40-16 victory over Australia.

Nevertheless, Jones insisted his men are not under any pressure, asking the press conference crowd to put up their hand if they thought England could win.

"There you go, so no one. No one thinks we can win," he said.

Jones, the coach of the Japan side that enjoyed a huge upset win over South Africa at the 2015 World Cup, joked that "there are 120 million Japanese people out there whose second team are the All Blacks. So there's no pressure on us".

Meanwhile he was adamant that New Zealand were in a very different situation.

"They've got to be thinking about how they're looking for their third World Cup (in a row) and so that brings some pressure," he said.

The coach has long had a reputation for pre-match mind games in the build-up to a Test.

When asked if he was making these comments in the expectation they would be read by All Blacks players, Jones laid into the New Zealand media for the supposed partisan nature of their rugby coverage.

"Well someone has to ask them (the All Blacks) a question because the New Zealand media doesn't - you guys are just fans with a keyboard," he said. "The English media - a week ago I was going to get sacked, we couldn't play - we deal with a completely different situation."