London, March 31 (IANS) Extra-terrestrial beings and UFOs might "drop by" at the wedding of Prince William and Kate Middleton, a retired air force pilot has claimed.

Major George Filer, who runs the National UFO Centre, said UFOs are "often spotted" during big national events, and might drop by at the royal wedding, according to The Sun.

"The craft seem to have an interest in anything important. They've been sighted recently over Libya and near the Japanese tsunami," he said.

Aliens were even more likely to visit London April 29 because the royal family has a special interest in UFOs, he said.

Filer said he met Prince Philip in the 1960s, and William's grandfather was fascinated by extra-terrestrial objects.

"It was around 1961 or '62, when I was a navigator in a tanker. He met us after a dinner because he wanted to talk about UFOs. He told us that the RAF (Royal Air Force) had stopped sending fighters after UFOs because some of them didn't come back."

Filer's centre tracks over 1,000 alien sightings every month.