A panel set up by Tokyo's Governor says the cost of hosting the Olympics in 2020 has blown out more than four-fold since Japan bid for the Summer Games.

Yuriko Koike was elected to her post on July 31, but has wasted no time in getting things done.

She headed straight for the biggest, most problem-riddled files on her desk and on top of that pile was the 2020 Olympic Games.

The bill for the games will be met by the International Olympic Committee, Japan's national Government and the Tokyo Metropolitan Government.

Loading

Governor Koike's job is to ensure Tokyo's share of the bill doesn't become an anchor for the host city in the years after the Olympic flame has been put out.

In 2013, the Olympic Bid Committee gave an estimate then that the event would cost $9 billion to stage.

But now that figure has been revised and the Tokyo Metropolitan Government estimates the real amount is closer to $39 billion. It sounds even more incredible in Japanese Yen - it will take 3 trillion of those.

Governor Koike asked a panel of experts to report back to her about where savings could be made.

The panel has handed down its report, suggesting that the venues for some sports should be changed.

It recommends that the plans for the aquatics centre - the site for the Olympic swimming events - be pared back or abandoned altogether in favour of refurbishing an existing swimming centre just down the road.

The panel raised concerns about the plans to build a customised volleyball stadium. What is proposed is a stylish building, but the panel said it won't get much use after the games.

The panel went as far as to suggest that the plans should be scrapped in favour of another, less glamorous building.

It didn't stop there. The panel also raised its concerns about the management of the games so far.

It said asking the Tokyo Metropolitan Government and the Olympic Organising committee to jointly oversee the Games was the "same as a company that doesn't have a president or a financial director".

Tense times for Olympic organisers

Tokyo's Olympics are still four years away, but already they have suffered huge embarrassment along the way.

First there was a scandal about the plagiarised logo for the Games; then came a replacement of the original stadium design.

If that wasn't embarrassing enough, it was then revealed that the new design didn't have an Olympic cauldron.

Tokyo and the Olympics First hosted the summer Olympics in 1964 Joins Athens, Paris, London and Los Angeles as one of just five cities chosen to host the Summer Olympics more than once Japan has also hosted the Winter Olympics Games twice, in Sapporo (1972) and Nagano (1998)

The president of the organising committee for the Olympic Games is Yoshiro Mori, a former prime minister of Japan.

Governor Koike asked Mr Mori for a meeting about the cost blowout and the potential venue changes on Thursday.

He arrived looking cranky. As far as he is concerned, what's done is done and there is no time for review.

"The venues were selected by everyone after getting approval from the Athletic organisations which took two and a half years and it was decided at the International Olympic Committee's board of directors meeting," Mr Mori said.

"I mentioned in the meeting that it's an extremely difficult issue to overturn this."

Governor Koike said she would review the options presented by the panel quickly and decide how to proceed.

Any changes she suggests would have to be approved by the individual sports federations and then again approved by the International Olympic Committee.

At the Governor's press conference in Tokyo on Thursday, the ABC was the last in line for the document outlining the venue changes and the pile ran out before we got one.

When we asked for one to be photocopied for us, the response was: "Sorry we can't, we are cost-cutting."