A Boeing 727 cargo plane, which has triggered panic among US intelligence agencies after mysteriously disappearing from Angola's main airport, reappeared last week in Guinea before vanishing again.

The plane, which was feared to be in the hands of international terrorists, was spotted on June 28 in Conakry, Guinea's capital, by Bob Strother, a Canadian pilot, The Guardian reported on Monday.

"There's absolutely no doubt it's the same aircraft, the old registration is clearly visible" said Strother by phone from Conakry. 

"Whoever owns it must have some important friends to get it re-registered in two days: going by the book, the whole process usually takes a couple of months," he said. "We only saw it that one time, now its gone."

The plane has been re-sprayed and given the Guinean registration 3XGOM. But at least the two letters of its former tail number, N844AA, were still showing, the report said.

The plane, which was recently converted into a fuel tanker, was said to be owned by a member of West Africa's Lebanese business community, and was being used to shuttle goods between Beirut and Conakry, according to Strother.

Immediately after the plane's disappearance, unnamed US intelligence sources told an international news agency that it 'most likely' was taken for a 'criminal endeavour such as drug or weapons smuggling'. 

But they had not ruled out the possibility it was stolen for use in a terrorist attack.