It looks like being a particularly grim Lunar New Year in the “tigers’ cage” this week. The notorious Qincheng maximum security prison houses many disgraced senior Communist Party officials – including fallen security chief Zhou Yongkang, former Chongqing boss Bo Xilai, ex-presidential aide Ling Jihua and Guo Boxiong, who was once a top general.

Normally, some of those prisoners who are aged over 60 can look forward to a Lunar New Year meal with a few family members, but a source close to the jail told the South China Morning Post that this year, the celebration has been cancelled.

The source said the prison was packed to the gills with inmates – a product of President Xi Jinping’s ferocious anti-corruption drive that has netted more than 1.3 million officials at various levels, from the elite “tigers” to the ordinary “flies” – and there was not enough room to accommodate the annual family gatherings during the most important Chinese festival of the year.

Adding to their woes, no visitors will be allowed for two weeks before and after the first day of the Lunar New Year, on Friday.

“The prison used to allow inmates over 60 to have a meal in jail with a limited number of their immediate family members ahead of the Lunar New Year. Some of them will have a hotpot, others bring dumplings, whatever they like,” the source said.

“But this year, the prison has cancelled the celebration with family – and not only that, they’ve also barred visitors for all inmates for the fortnight leading up to and following the new year.”

Located on the northern outskirts of Beijing at the foot of the Yan mountains in Changping district, about an hour’s drive from the centre of the capital, the secretive Qincheng prison is set aside for officials with a ranking of vice-ministerial level or above.

But Xi’s unprecedented graft-busting campaign over the past five years means the “tigers’ cage” is running out of cells.

Over the years, many household names have been imprisoned within its walls – including Jiang Qing, widow of Chairman Mao Zedong, Bo Yibo, revolutionary party veteran and late father of Bo Xilai, Peng Zhen, former chairman of the National People’s Congress Standing Committee, Chen Xitong, former party boss of Beijing, and Chen Liangyu, the ex-Shanghai party chief who is still serving his sentence for fraud, abuse of power and bribery.

Unlike Club Fed, the term used for low-security jails in the United States where white-collar criminals and VIPs do time, prisoners at Qincheng are closely monitored and some former inmates have said they were mistreated there.

One leader of the 1989 Tiananmen pro-democracy movement who was imprisoned after the crackdown and released over a decade ago said every Qincheng inmate was kept in solitary confinement in a cell of about 16 to 20 sq m at that time.

But he said the former high-ranking officials – including ex-Politburo members – were kept in a north-facing, U-shaped building.

“Unlike in the chaotic Cultural Revolution era, when Qincheng was full of counter-revolutionaries and every cell was occupied, the number of inmates had dropped sharply when I was jailed – there were plenty of cells.

“The U-shaped building was renovated and the 10 cells down each side were turned into five bigger ones. If any of the five cells was occupied by a disgraced Politburo member, the other four in the row would be kept empty,” he said.

Qincheng has been shrouded in secrecy since it was built, with the help of the Soviet Union, in 1958 to imprison war criminals from the Communist Party’s arch-rival, the Nationalist Party or Kuomintang.

Overcrowding also became a problem back then, during the Cultural Revolution that began in 1966, when elite politicians were purged, although it was expanded and refitted in the 1960s.

In recent years, with nearly 100 new “tigers” convicted – including Zhou, Bo Xilai and his former right-hand man Wang Lijun, ex-railways minister Liu Zhijun and Su Rong, former vice-chairman of the top political consultative body – the jail is nearly at full capacity.

And that is after Qincheng was reportedly expanded in 2012, months before Xi began his war on corruption when he took office.

A relative of a former official brought down in the anti-graft drive who has been serving time in Qincheng since late 2013 said the prison had become increasingly crowded as Xi’s campaign gathered pace.

“He told me there were no more than six inmates in his area when he arrived. Now, because of the crackdown, there are more than 20 people in the block,” the relative said, adding that she normally went to the jail every month.

Inmates are still largely kept in solitary confinement at Qingcheng, although they do have the opportunity to interact with other prisoners during exercise and interest group sessions.

But when Yan Mingfu, former head of the party’s United Front Work Department, spent seven years there from the late 1960s, inmates were strictly forbidden from interacting with each other, according to his memoir.

By the time Bao Tong, former secretary to the party’s late General Secretary Zhao Ziyang, served his seven-year term for opposing the crackdown on the democratic movement in 1989, inmates were being closely watched and were kept in cells divided by walls that were thick enough for guards to patrol on top of them, he told media.

Conditions may have improved since then. The source close to the prison said inmates did have a chance to interact with each other during interest groups that included gardening, and they were also allowed out of their cells every day for an hour or two to exercise in an open-air courtyard, when they could also talk to the other inmates.

“Bo Xilai appears to be in good spirits and takes part in various activities,” the source said. “But Guo and Ling never show up for these activities, they don’t take part in any of them. Guo seems to be suffering from an illness that stops him from going out. Ling Jihua could be a bit depressed – he’s the only inmate as far as I know who has never had a single relative or friend visit him over the years.”

The source added that former security tsar Zhou – the first Politburo Standing Committee member to be jailed for corruption – had access to a private courtyard and was kept separate from the rest of the prisoners.

Qincheng is the only jail in China run by the Ministry of Public Security – the rest are run by the Ministry of Justice . When it opened, it had flush toilets, medical clinics and fitness facilities that would have been unavailable to most Chinese in the late 1950s.

But the Tiananmen pro-democracy leader said that when he was imprisoned in Qincheng, there was nothing cushy about it – even for the VIPs.

“One day I came across Zhang Chunqiao, one of the ‘Gang of Four’  during the Cultural Revolution. He’d just left his cell in the U-shaped building to take a shower – so even Zhang, who was on the Politburo Standing Committee before he fell from grace, didn’t have a bathroom in his cell. It wasn’t exactly luxurious.”