Bosnia's mystery pyramid will now be probed and inspected by a team of experts from the U.N. Educational, Scientific and Cultural Organization.
"We shall send a UNESCO expert team to Visoko to determine exactly what it is all about," UNESCO Secretary General Koichiro Matsuura said in an interview published on Monday in Dnevni Avaz newspaper.
Amateur archaeologist Semir Osmanagic has caused a stir with his find, although local and European archaeologists denounce it as nonsense.
Geologist Aly Abd Barakat, an Egyptian researcher sent by Cairo to assist Osmanagic's team last month, has said that the Visocica hill did appear to be a primitive man-made pyramid of uncertain age.
Barakat said huge stone blocks found on the three sides of the hill used the same type of artificial cement used in ancient Egyptian pyramids.
Osmanagic's team is also investigating the Pljesevica hill -- which he calls the Moon Pyramid -- as well as underground tunnels he believes connect three pyramids.
The researchers have also found a sandstone monolith in the underground tunnel with enigmatic symbols engraved on it, which will be sent to Egypt for analysis.
Osmanagic, who studied pyramids in central America for the past 15 years, said that satellite and radar analyses have revealed the perfect geometry of Visocica and precise alignment of its sides with four cardinal points.