The London-based architect group that won the first contest to redesign the National Stadium for the 2020 Olympic Games said Wednesday it is investigating similarities between its ill-fated design and design A, the winner of the second contest.

Architect Kengo Kuma’s team was declared the winner of the second competition for the stadium on Tuesday, edging architect Toyo Ito. The original proposal by Zaha Hadid Architects was abandoned in July amid a public outcry over costs.

“The design team is currently reviewing the detailed designs and investigating similarities,” a ZHA representative said.

It is unclear whether the group will take legal action. ZHA informed the Japan Sport Council in August that all of the original plan’s design work was the intellectual property of the architect.

After Tuesday’s announcement, ZHA issued a statement claiming there were “remarkable similarities” between its design and the new one, particularly in the detailed stadium layout and seating bowl configuration.

Ito, the architect behind losing design B, said Tuesday he also noticed similarities.

“I wonder if it is almost entirely based on Hadid’s plan. Its appearance is different, but if you look under the surface, there are details that seem almost unchanged,” Ito said.

ZHA’s design was renounced by Prime Minister Shinzo Abe this summer amid public outcry over its ballooning costs. The price tag was projected to hit ¥265.1 billion ($2.19 billion), more than double the initial estimate and one of the most costly stadiums ever.

Kuma’s winning design will cost an estimated ¥149 billion and has a completion date of November 2019.

The design was chosen based on an evaluation of nine categories associated with cost, construction period and execution plan.

The design features steel and wood architecture, a flat roof and a sunken seating bowl that will accommodate 80,000 people.

Taisei Corp. and construction support firm Azusa Sekkei, who are part of Kuma’s design team, were also involved in the original design led by Hadid.