The suspect in the deadly arson attack on a Kyoto Animation Co. studio in July, who is in hospital with severe burns, has recovered to the extent that he can practice speaking again, investigative sources said Wednesday.

Police have obtained an arrest warrant for Shinji Aoba, 41, on suspicion of murder and arson among other charges, but are not currently able to arrest him as it is up to doctors to determine whether he can withstand confinement.

The company’s studio in Fushimi Ward, Kyoto, the center of its anime production, was set ablaze on July 18 after gasoline was spread and ignited inside the three-story building, killing 35 people and injuring 34.

Aoba was apprehended by local police near the scene and was temporarily in a critical condition, but recovered to the extent that he could make simple gestures in early August.

According to the sources, Aoba has undergone skin graft surgery and is now in a stable condition. Though he is still being treated in an intensive care unit and needs a ventilator, he will be undergoing rehabilitation including speech therapy, the sources said.

As it is expected to take several more months before he is released from the hospital, the police are considering how best to proceed with their investigation, the sources said.

Kyoto Animation, often referred to by fans as KyoAni, is known for works such as “K-On!” and “The Melancholy of Haruhi Suzumiya,” which depict the everyday lives of high school girls.

Donations to the studio have exceeded ¥2.5 billion ($23 million), but it is likely to take some time for the company to recover. About 20 percent of its employees lost their lives in the incident.

Among the 69 members of staff who died or were injured, some 75 percent were in their 20s and 30s. The company is known to hire young animators as regular employees and conduct in-house training, in contrast to many other studios that tend to rely on skilled freelancers.

Though some of the injured employees have returned to work, others have remained unable to do so for psychological reasons, the investigative sources said.

As a measure to support the firm’s recover, the Kyoto Prefectural Government has set up a special bank account to accept donations.

Donations transferred to the bank account will be regarded as contributions to a local government so will be eligible for tax relief.

On Sept. 6, a film created by the anime studio — completed a day before the incident — was released for the first time since the arson attack, attracting many fans.

But the release of the next movie in the series, originally scheduled for January next year, has been postponed, according to Kyoto Animation.