A diplomat said Jamie Shea, the alliance's chief spokesman, wanted the tape - recorded by a camera on the F-16 attack aircraft - placed in the public domain but had failed to win the agreement of military chiefs investigating the episode.
Another source pinned the blame for the delay on its release on the US, arguing that its air force needed to agree to release the material. The Pentagon is sensitive about the attack because its pilot and air crew were responsible.
The row over the withheld tape dominated the reports yesterday, almost masking the escalation of military efforts by the alliance and Belgrade.
The dispute came amid continuing confusion as to which column the Nato plane attacked on Wednesday and where the attack was. On Thursday, Nato admitted it attacked a column that it took to be a military convoy before hitting another three vehicles in a nearby compound. It is believed these attacks were north of the Kosovo town of Djakovica, near the village of Meja. Nato also said it attacked a military convoy on a bridge near the village of Zrze, south of Djakovica.
At a Nato briefing in Brussels, Mr Shea said Nato only accepted blame for one incident, adding that admission of one mistake did mean every incident should "be laid at Nato's feet". He also dismissed new claims by Belgrade that in a separate incident Nato had struck a refugee centre in the Serbian town of Paracin overnight. But Nato is finding it difficult to explain the pictures on Serb television - apparently taken near Zrze - of mangled bodies and farm machinery.
Against this backdrop, the outcome of the battle over whether or not to release the video footage of the attack could prove crucial. Although the images could be damaging to public opinion, Nato's failure to be seen to come clean could also dent its credibility.
Nato diplomats said there was no cover-up by Mr Shea: "He wants its release as much as the media does. If they [Nato] had wanted to hide the existence of the tape, they would not have allowed it to be known that the pilot dispatched a laser-guided bomb".
The formal investigation into the bombing of the column is being carried out at the Supreme Headquarters Allied Powers Europe, which is resisting release of the video.
"It's a military decision - it's their decision what they do with it", said a source. "They want to be careful that they don't give out any information that turns out not to be true before the investigation is completed and they want a complete and thorough investigation."
But as the doubt and confusion last night swirled over Djakovica, other things were crystal clear - that the war is escalating, that Kosovo's desperate humanitarian crisis is deepening further, and the risk of the conflict spreading into other countries is becoming ever more apparent. According to the United Nations High Commission for Refugees, a further 100,000 refugees are on the way to the Macedonian border, including 50,000 from the Gnjilane region in southern Kosovo. In addition, 5,000 people crossed over into Albania yesterday, as reports multiplied of Serb forces systematically emptying towns and villages of their populations and laying waste to the land.
If the figures are remotely accurate, it will mean that a third of the ethnic Albanian population have been driven from the province, apart from the unknown numbers still within it, caught between intensifying bombardment from the air and ethnic cleansing on the ground.
Among planners in Nato capitals the urgency is growing. In Washington, the Pentagon announced it was considering calling up 33,000 reservists, while George Robertson, the Defence Secretary, inched closer to sending Nato ground troops to drive the Serbs from Kosovo by force. Officially, such a move is not on the table, but Mr Robertson left the option open, saying that plans "must be kept under review".
Meanwhile, Nato is stepping up the aerial pounding, hitting a range of targets in and around Belgrade yesterday, as well as in Montenegro, Serbia's junior and sole remaining sister republic in the Yugoslav Federation. Allied warplanes had "one of the best nights yet", according to Nato, claiming hits on tanks, MiG fighters, artillery and anti-aircraft installations.
Nato officials insist that the allied hammering of Serb positions, disrupting fuel supplies and communications, was helping the lightly armed Kosovo Liberation Army guerrillas step up their marauding against Milosevic forces.
In Montenegro, however, attacks on Yugoslav army and naval sites have only increased fears that the republic, relatively sympathetic to the West, could fall prey to a coup by Yugoslav army officers and pro-Belgrade politicians, which could unleash a civil war.
Appealing for an immediate end to the fighting, Milo Djukanovic, Montenegro's President, warned that the war was spinning out of control. Though he dismissed the idea of a coup as "not feasible", he spoke grimly of a wider Balkan conflagration: there was "an objective danger the Kosovo fire and blood could engulf not just Yugoslavia but the entire region". If civil war did break out in Montenegro, "it would be more tragic and worse than anything ... in this area".
As if to underline his warning, Serb and Albanian forces exchanged fire for five hours across the frontier near the north Albanian village of Bajram Curri. Serb soldiers had tried to cross the border, but had been pushed back, an Albanian statement said. Analysts fear a generalised war between Serbs and Albanians, sucking in Montenegro and Macedonia too.
Further afield in the Balkans, the conviction is growing that only after Mr Milosevic's removal from power can stability return to south-eastern Europe. Urging the opening of a ground campaign, the Croatian Deputy Prime Minister, Borislav Skegro, declared that "keeping Milosevic in power does not solve anything" - a sentiment echoed by his Bulgarian opposite number Alexander Bozhkov at a conference yesterday in London.
On the diplomatic front, movement has come to a virtual standstill. Mr Milosevic did meet the ethnic Albanian political leader, Ibrahim Rugova, yesterday. But the influence of Mr Rugova, who advocated a non-violent solution to the crisis, is now close to zero.
Leading article, Review page 3, Fergal Keane, Review, page 3Reuse content