The chief architect for the new headquarters of China's state broadcaster said preparations are under way to begin reconstruction soon on part of the complex that was burned in a massive fire triggered by illegal fireworks display earlier this year.

Architect Ole Scheeren said the investigation into the fire that damaged a China Central Television building is "near its conclusion."

"The reconstruction has not yet officially begun," he said. "However preparations are under way for the start, but no specific date has yet been set."

Scaffolding is visible around the perimeter of the charred tower, though no workers have been spotted on site.

In February, the 159-m, 44-story building, known as the Television Cultural Center, was engulfed in flames after an illegal fireworks display arranged and paid for by CCTV to mark the end of the Lunar New Year festivities. One fireman died fighting the blaze.

The building had housed the nearly completed luxury Mandarin Oriental Hotel, television studios, an exhibition space and a visitors' center. It is part of the same 5-billion-yuan ($735-million) complex that houses the iconic, futuristic-looking CCTV headquarters designed by Scheeren and famed partner Rem Koolhaas.

More than a dozen people have been arrested for the accident, including the former boss of CCTV's construction bureau, Xu Wei. News reports have alleged he ordered the powerful pyrotechnics to be used, while ignoring safety warnings.

Scheeren said preliminary findings indicate the main concrete structure of the damaged building does not have to be torn down. The main CCTV building itself was not damaged, he said.

"The preliminary findings are that the building can be repaired," he said. "It's still intact and safe. There will mainly be a repair effort but not a complete rebuilding."

Scheeren gave no further details on a timeline for the reconstruction. But he said his firm, OMA, is continuing to work on the main CCTV headquarters and expects that work to be completed by next year.