The only videotape known to have recorded both planes slamming into the twin towers of the World Trade Center and the only second image of its kind showing the first strike has surfaced publicly almost two years after terrorist attacks brought down the New York landmark.

The only other video tape showing the first plane hitting one of the towers came from a French crew who was making a documentary about firefighters.

• More News Reports

The footage, which just surfaced, was shot by a Czech immigrant construction worker Pavel Hlava, who knows little English, and has now been obtained by the New York Times.

The immigrant's son came very near erasing the recording at one point of time but the father took the video camera away in the nick of time.

• Americans fear new terror strike within a year

One of the reasons for tape not surfacing so long was that the immigrant was not sure what to do with it though he knew he had recorded the most deadly event in the United States.

Federal investigators who are studying the collapse of the towers say they are now trying to obtain a copy for the data it may contain.

A lack of information on the first strike, for example, has posed a major challenge to engineers trying to understand exactly why the north tower crumbled.

The tape could, for example, help investigators pin down the precise speed at which the first plane was moving when it struck the tower.

Reporting the acquisition of tape, the New York Times said Hlava was making a video to be sent home when he captured the planes impacting the twin towers and at that time, he did not realise the gravity of the incident.

It was not until almost two weeks later that he even realised that he had captured the first plane on video.

Even then, Hlava did not realise that he had some of the rarest footage collected of the World Trade Center disaster. His is the only videotape known to have recorded both planes on impact, the Times reported.

The tape - a kind of accidentally haunting artefact - has surfaced after following the most tortuous and improbable of paths, from an insular circle of Czech-American working-class friends and drinking buddies.

At one point, a friend of Hlava's wife traded a copy of the tape to another Czech immigrant for a bar tab at a pub.

Hlava and his brother, Josef, who was also in the car on September 11 tried at various times to sell the tape, both in New York and in the Czech Republic.

But with little sophistication about the news media and no understanding of the tape's significance, the bothers had no success, the Times said.

Eventually, a woman happened to learn of the tape from the pub deal at a school where one of the Czech immigrants was studying English. She brought it to the attention of a freelance news photographer who doubled as her ballroom dancing partner, and that man, Walter Karling, brought the tape to the New York Times.

In an interview with the Times on Thursday, Hlava said through a translator - David Melichar, who with Karling now describes himself as Hlava's agent - that the language barrier had much to do with why no one beyond his family and friends had seen the tape.

Finally, Hlava said, so much time had passed that he doubted anyone would still be interested.

"All his friends, they told him, Hey, you made a mistake. You waited too long," Melichar said.

Melichar also made it clear that the driver of the car had strong objections to releasing the tape. And because the driver, a Russian native named Mike Cohen, is Hlava's boss on his construction job, that wish carried a certain weight.

"Three thousand people died in that place," Cohen said when reached on his cell phone on Friday. "I told him the day he's gonna sell that film, he's not gonna work for me anymore."

Karling said on Saturday that The New York Times had not paid for the tape, and that it had not been sold to any television station.

PTI