The man, a security consultant in his 30s, posted sections of the programme to a hacking forum where he described it as something he was working on, the paper said, quoting an unidentified researcher working for the U.S. government.
The spyware creator works as a freelancer and did not launch the attack, but Chinese officials had special access to his programing, the report said.
If he wants to do the research he's good at, he has to toe the line now and again, the paper quoted the unnamed U.S. government researcher saying.
He would rather not have uniformed guys looking over his shoulder, but there is no way anyone of his skill level can get away from that kind of thing. The state has privileged access to these researchers' work.
The report did not say how analysts knew about the man's government ties.
The allegations over the spyware are the latest episode in a dispute that has pitted Google and the United States against China, with its wall of Internet controls and legions of hackers.
In January, the giant Internet search engine company, Google, threatened to pull back from China and shut its Google.cn Chinese-language portal over complaints of censorship and sophisticated hacking from within China.
Washington has backed those criticisms and urged Beijing to investigate hacking complaints thoroughly and transparently. Beijing has said it opposes hacking.
The Financial Times report also quoted unnamed sources backing a New York Times report that analysts had traced the online attacks to two Chinese educational institutions, the prestigious Shanghai Jiaotong University and the Lanxiang vocational school.
The two establishments have denied the reports. And the allegation that the latter, a high-school level institute that also trains hairdressers, chefs and car mechanics, could take on one of the world's most powerful Internet firms, have been widely mocked in Chinese cyberspace.
How can these future cooks be such powerful hackers? a web user from Zhejiang province said on the portal www.163.com.
The use of the school's IP address could simply mean that hackers had taken over its computers to hide their tracks.
But Lanxiang's website also claims to have the biggest computer laboratory in the world, a boast it says is confirmed by Guinness World Records.
There was less online comment about the well-respected Jiaotong University, which attracts top graduates and has a School of Information Security Engineering.
(Reporting by Emma Graham-Harrison; Editing by Alex Richardson)