Whatever else WikiLeaks may have revealed, one fact has been repeatedly confirmed: the US government under George Bush really loathed the documentary filmmaker Michael Moore.

After a leaked cable from US diplomats in Havana falsely claimed Cuba had banned Moore's documentary Sicko – when in fact it was shown on state television – another cable reveals US officials flying into a panic after hearing a rumour that a New Zealand cabinet minister was hosting a screening of Moore's film Fahrenheit 9/11.

Labelling the event a "potential fiasco", the classified cable from the US embassy in Wellington in 2003 reads like a failed plotline for an episode of In the Loop, breathlessly reporting a series of calls to the New Zealand prime minister's office and to the minister involved, Marian Hobbs.

Michael Moore, appearing on the Rachel Maddow Show on Tuesday night, said the New Zealand cable uncovered by WikiLeaks showed the unsettling reach of US influence. "If they were micromanaging me that much, if they were that concerned about the truth in Fahrenheit 9/11 that they have to go after a screening in a place I don't even really know where it is – I know it's way too long to sit in coach for me – I want to know. Because I think it speaks to a larger issue: if they have the time for that, what else are these guys up to?"

Sadly for the world's only superpower, the New Zealand government wasn't concerned in the slightest, based on the puzzled responses recorded by the US deputy chief of mission, David Burnett, to his protests.

Burnett contacted the prime minister's office, to be told they knew nothing about a screening. He then called Hobbs, only to be rebuffed by a receptionist. "The minister's office declined to make her available to discuss the matter," Burnett sniffed.

Hobbs's staff later told the US embassy that she was merely attending the screening, part of a series of Labour party fundraisers in her constituency.

The Americans tried to console themselves with bluster, assuring colleagues in Washington that they had saved the day in the face of New Zealand's latent indifference. "It is probable that this potential fiasco may only have been averted because of our phone calls – it is apparent to us that neither the minister nor anyone else in the Labour government seems to have thought there was anything wrong with a senior minister hosting such an event."

The participants on the New Zealand side remember little, if anything, about the "potential fiasco".

Hobbs, who retired from politics in 2008 and now works in Northampton, told the Guardian she did not recall the event that merited a superpower's intervention.

"To be honest I can't remember anything about it at all," she said. "Possibly my staff didn't tell me because they knew I wouldn't take any notice."

Grant Robertson, who worked as a volunteer campaign official for Hobbs and helped organise fundraising events, recalls a "bit of a fuss" but can't remember minor details – such as the diplomatic might of the US state department being involved.

"Yes, I remember the event. It was one of a number of similar movie fundraisers, and I remember that it went ahead," said Robertson, who replaced Hobbs as Labour MP for the Wellington Central seat. "I have a memory of a fuss but it wasn't much of a fuss."

The Americans seemed to think so. The cable concludes: "Ambassador will use a scheduled meeting with the prime minister to tell [Helen] Clark … that we would really rather not get dragged into internal political issues, such as ministerial fundraising events for Clark's Labour party."

The US ambassador to New Zealand at the time was Charles Swindells, appointed to the post by George Bush in 2001, having been a prolific fund-raiser for Bush's 2000 election campaign.