Citing police, the official Xinhua news agency also reported that three other CCTV employees and eight people hired by the broadcaster to set off the fireworks had also been detained.
The eight fireworks operators, from a fireworks company based in Hunan province in central China, fled the scene once the blaze began, Xinhua said.
They were caught by police in the city of Langfang, about two hours drive south of Beijing.
|Fire authorities claim CCTV staff used powerful and illegal fireworks [Reuters]
The fire began on Monday evening, and according to fire authorities, was caused by fireworks that CCTV had illegally set off at its new headquarters to celebrate the end of Lunar New Year festivities.
The fire quickly spread through a 30 storey tower in the complex, and it was several hours before firefighters were able to bring the blaze under control.
One fireman was killed in the fire.
CCTV is said to have used fireworks more powerful than the public were allowed to buy, and ignored police orders for them not to be set off.
The unfinished 30-storey tower was to have housed a new Mandarin Oriental Hotel, as well as a television studio and an IT centre.
Officials have yet to say whether it will have to be destroyed.
In the wake of the fire Pan Shiyi, chairman of SOHO China, a major property firm based in the Chinese capital, submitted a proposal to officials that a 2005 decision to lift restrictions on Chinese New Year fireworks in downtown Beijing be reversed.
He said that fireworks had made celebrations more lively but at the cost of serious dangers, nuisance, pollution and Beijing's reputation.
"They are inconsistent with Beijing's image as a major international capital," he wrote in the proposal.
"We ought to establish appropriate civilised standards for a modern capital."