Tokyo governor Yuriko Koike has sworn to take action against officials who were found to have cut corners at the new site of the historic Tsukiji fish market.
The 81-year-old market, the world's largest wholesale fish and seafood market, was slated to be relocated on Nov 7 to make way for a major highway meant to ease traffic gridlock at the main venue for the 2020 Tokyo Olympic Games.
But Ms Koike, a former environment minister, has indefinitely put these plans on ice after revelations that the new site at Toyosu, a former gas production plant, might not be as safe as initially thought.
Speaking at the Tokyo Metropolitan Assembly on Wednesday, Ms Koike, who was elected to office on July 31, pledged to "overhaul the way the market is run".
She has been roundly criticised by Tokyo assemblymen for failing to consult them before deciding to put off the relocation.
Former Tokyo governor Shintaro Ishihara, who announced the relocation plans in 2001 and the move to the Toyosu site in 2010, has flatly refused to attend the assembly hearings in a volte-face from earlier pledges to "thoroughly cooperate" with the ongoing probe.
He pleaded ignorance last month, claiming to have been "cheated" and saying the metropolitan government was "full of demons".
I'll wait for an objective judgment (on the safety issues). Then I want to choose the wisest way to spend taxpayers' money.
TOKYO GOVERNOR YURIKO KOIKE, on the relocation of Tsukiji market.
The move was first put off for a seemingly innocuous reason - Ms Koike wanted to wait for results of a groundwater test that was due in November, saying it was "illogical" to move before the report was out.
Tokyo had run seven such tests since 2014 at the new site, all of which showed that it was safe.
But since then, news of the Toyosu site, a gas plant from 1956 to 1988, has gotten much worse.
First, it was discovered that it is missing a layer of clean soil, supposed to be 4.5m deep, that experts say is necessary to insulate the site from toxic contaminants.
In its place are underground concrete chambers that serve as utility rooms and are filled with pipes and electrical cables.
Flooding was discovered last month, and the groundwater found to be tainted with traces of arsenic, though within safe limits.
An inquiry called by Ms Koike into the mess showed that four of five market chiefs in the last 10 years - including the incumbent chief - were under the impression that the entire site would be covered with the 4.5m-deep layer of clean soil. The inquiry unearthed a chronic culture of poor communication.
The delay prompted a series of tests, some independent, into the soil and water quality at the new site, with mixed results. One test in August discovered toxins at an area meant for fruit and vegetables, with the level of benzene 1.4 times and the level of arsenic 1.9 times the respective standards.
More startlingly, a report by the Asahi Shimbun daily earlier this week noted that levels of benzene and cyanide were 700 times the environmental limits under the walkways of two key facilities at the site. These walkways were not deemed by metropolitan officials to be part of the market compound, and so clean-up work was not done there.
Ms Koike, who campaigned on a platform of transparency, has said she will decide when to relocate the Tsukiji fish market after a "comprehensive examination" confirms the safety of the new site.
She has not ruled out killing the 588.4 billion yen (S$7.8 billion) move altogether. She said: "I'll wait for an objective judgment (on the safety issues). Then I want to choose the wisest way to spend taxpayers' money."