What do the late Pink Floyd vocalist Syd Barrett, the Canadian actor Erica Durance and Brazilian model Felipe Berto have in common?

They all suddenly appear to be big supporters of China's policies in Tibet.

Not that they had any say in the matter. Chinese propagandists have opened scores of fake accounts on Twitter to promote Beijing's line on the ethnically divided Himalayan region, many of which were suspended by Twitter on Tuesday.

The accounts – identified by the London-based advocacy group Free Tibet – use names such as Tom Hugo, Ken Peters and Felix James. Some apparently lifted their profile pictures from stock photo websites, other active accounts and the internet at large to include images of Barrett, Berto and Durance (who played Lois Lane in the Superman-inspired American TV series Smallville), as well as myriad western models.

The tweets – written in English and Chinese – attack political leaders' meetings with the Dalai Lama, advertise rail links between China's east coast and Lhasa, the Tibetan capital, and link to videos of Tibetans dancing in "exotic dress" on state-run television.

Others celebrate claims of progress under Chinese rule ("Tibetans hail bumper harvest of highland barley," Tom Hugo posted in October 2013, below a picture of a smiling Tibetan woman holding a sickle) while a subset trumpet development projects in the troubled north-western region Xinjiang.

Harder to categorise are posts that are merely strings of gibberish.

While the accounts cannot be conclusively linked to Communist party authorities, the sheer scope of the initiative suggests state backing, said Free Tibet's press and media manager Alistair Currie. "It's hard to imagine anyone getting any benefit from this project other than the Chinese government," he said.

Although Twitter and Facebook are blocked in mainland China – the government banned them when riots spread across Tibet in 2008 – municipal governments have begun to launch Facebook campaigns to draw international tourists, and state-run newspapers maintain robust Twitter feeds.

Free Tibet found that the fake accounts had overlapping qualities. Most of their names were comprised of two western-sounding first names strung together. About 90 of them were also closely intertwined – they followed one another and frequently retweeted each other's posts, often identical statements and links.

"Then there was a larger circle of accounts with more followers, some of whom looked genuine, many of whom were extremely suspicious," Currie said. "Based on our original research, we think the scope of this is beyond the capacity of our organisation to investigate."

On Monday night, before the accounts were suspended, the Free Tibet director Eleanor Byrne-Rosengren wrote a letter to the Twitter CEO Dick Costolo, urging the service to bar authoritarian governments from using it to spread propaganda.

Tibetans in Tibet "face even greater restrictions on their online activity than China's own citizens and can receive sentences of up to life imprisonment for online or email content criticising China's regime," she wrote. "China has the power and resources to use Twitter for its own ends and Tibetans do not. In the words of concentration camp survivor Elie Wiesel, 'neutrality helps the oppressor, never the oppressed'."